DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
S068521
14. Diagnostic Procedure with Diagnostic Trouble Code (DTC) A: DTC 11 CRANKSHAFT POSITION SENSOR
•  DIAGNOSIS:
•   No signal entered from crankshaft position sensor when ignition switch is ON.
•  The harness connector between ECM and crankshaft position sensor is in short or open.
•  TROUBLE SYMPTOM:
•   Engine stalls.
•   Restarting impossible
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-373.jpg
EN(SOHCw/oOBD)-68
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK CONDITION OF CRANKSHAFT POSITION SENSOR INSTALLATION.
Are the crankshaft position sensor installing bolts tight­ened securely?
Go to step 2.
Tighten crankshaft position sensor installing bolts securely.
2
CHECK CRANKSHAFT POSITION SENSOR.
1) Remove crankshaft position sensor. 2) Measure resistance between connector terminals of crankshaft position sensor. Terminals No. 1 - No. 2:
Is the resistance between 1 and 4 kQ?
Go to step 3.
Replace crank­shaft position sen­sor.
3
CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CON­NECTOR.
1) Connect connector to crankshaft position sensor. 2) Disconnect connector from ECM. 3) Measure resistance of harness between crankshaft position sensor connector and ECM. Connector & terminal (E22) No. 14 - (E22) No. 20:
Is the resistance between 1 and 5 kQ?
Go to step 4.
Repair harness and connector. NOTE: In this case, repair the follow­ing: • Open circuit in harness between crankshaft posi­tion sensor and ECM connector
4
CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CON­NECTOR.
Measure resistance of harness between ECM connector and chassis ground. Connector & terminal (E22) No. 20 - Engine ground:
Is the resistance less than 10 Q?
Repair ground short circuit in harness between crankshaft posi­tion sensor and ECM connector.
Go to step 5.
5
CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to OFF. 2) Disconnect connector from ECM, then con­nect ST. <Ref. to EN(SOHCw/oOBD)-23, HOW TO CHECK I/O SIGNAL FOR ECM, Engine Control Module (ECM) I/O Signal.> ST 498307600 CHECK BOARD KIT 3) Set the positive (+) probe and ground lead of oscilloscope at ECM connector terminals. 4) Measure voltage indicated on oscilloscope while cranking the engine. Connector & terminal (B) No. 26 (+) - (B) No. 19 (-):
Is the voltage more than 400 mV?
Go to step 6.
Replace crank­shaft position sen­sor.
6
CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
Repair poor con­tact in ECM con­nector.
Go to step 7.
7
CHECK ECM.
1) Connect all connectors. 2) Erase the memory. <Ref. to EN(SOHCw/ oOBD)-31, Clear Memory Mode.> 3) Perform inspection mode. <Ref. to EN(SOHCw/oOBD)-29, Inspection Mode.> 4) Read out the trouble code. <Ref. to EN(SOHCw/oOBD)-27, Read Diagnostic Trouble Code.>
Is the same trouble code as in the current diagnosis still being output?
Replace genera­tor.
Go to step 8.
8
CHECK ANY OTHER TROUBLE CODES APPEARANCE.
Are other trouble codes being output?
Proceed with the diagnosis corre­sponding to the trouble code.
A temporary poor contact.
EN(SOHCw/oOBD)-69
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
B: DTC 21 ENGINE COOLANT TEMPERATURE SENSOR
S068521G58
•  DIAGNOSIS:
•  The engine coolant temperature sensor signal is abnormal.
•  The harness connector between ECM and engine coolant temperature sensor is in short or open.
•  TROUBLE SYMPTOM:
•   Hard to start
•   Erroneous idling
•   Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-374.jpg
EN(SOHCw/oOBD)-70
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK HARNESS BETWEEN ENGINE
Is the voltage more than 10
Repair battery
Go to step 2.
COOLANT TEMPERATURE SENSOR AND
V?
short circuit in
ECM CONNECTOR.
harness between
1) Turn ignition switch to OFF.
ECM and engine
2) Remove air intake duct and air cleaner
coolant tempera-
assembly.
ture sensor con-
3) Disconnect connector from engine coolant
nector.
temperature sensor.
4) Measure voltage between engine coolant
temperature sensor connector and engine
ground.
Connector & terminal
(E8) No. 2 (+) - Engine ground (-):
2
CHECK HARNESS BETWEEN ENGINE
Is the voltage more than 10
Repair battery
Go to step 3.
COOLANT TEMPERATURE SENSOR AND
V?
short circuit in
ECM CONNECTOR.
harness between
1) Turn ignition switch to ON.
ECM and engine
2) Measure voltage between engine coolant
coolant tempera-
temperature sensor connector and engine
ture sensor con-
ground.
nector.
Connector & terminal
(E8) No. 2 (+) - Engine ground (-):
3
CHECK HARNESS BETWEEN ENGINE
Is the voltage more than 4
Go to step 4.
Repair harness
COOLANT TEMPERATURE SENSOR AND
V?
and connector.
ECM CONNECTOR.
NOTE:
Measure voltage between engine coolant tem-
In this case,
perature sensor connector and engine
repair the follow-
ground.
ing:
Connector & terminal
• Open circuit in
(E8) No. 2 (+) - Engine ground (-):
harness between
ECM and engine
coolant tempera-
ture sensor con-
nector
• Poor contact in
engine coolant
temperature sen-
sor connector
• Poor contact in
ECM connector
4
CHECK HARNESS BETWEEN ENGINE
Is the resistance less than
Go to step 5.
Repair harness
COOLANT TEMPERATURE SENSOR AND
5Q?
and connector.
ECM CONNECTOR.
NOTE:
1) Turn ignition switch to OFF.
In this case,
2) Measure resistance of harness between
repair the follow-
engine coolant temperature sensor connector
ing:
and engine ground.
• Open circuit in
Connector & terminal
harness between
(E8) No. 1 - Engine ground:
ECM and engine
coolant tempera-
ture sensor con-
nector
• Poor contact in
engine coolant
temperature sen-
sor connector
• Poor contact in
ECM connector
EN(SOHCw/oOBD)-71
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
5
CHECK ENGINE COOLANT TEMPERA-
Is the resistance between 2
Go to step 6.
Replace engine
TURE SENSOR.
and 3 kQ at 20°C (68°F)?
coolant tempera-
Measure resistance between engine coolant
ture sensor. <Ref.
temperature sensor terminals.
to FU(SOHCw/
Terminals
oOBD)-23, Engine
No. 1 - No. 2:
Coolant Tempera-
ture Sensor.>
6
CHECK ENGINE COOLANT TEMPERA-
Is the resistance between
Go to step 7.
Replace engine
TURE SENSOR.
0.35 and 0.4 kQ at 80°C
coolant tempera-
Measure resistance between engine coolant
(176°F)?
ture sensor. <Ref.
temperature sensor terminals.
to FU(SOHCw/
Terminals
oOBD)-23, Engine
No. 1 - No. 2:
Coolant Tempera-
ture Sensor.>
7
CHECK ENGINE COOLANT TEMPERA-
Is the resistance between
Replace ECM.
Replace engine
TURE SENSOR.
0.2 and 0.3 kQ at 90°C
<Ref. to
coolant tempera-
Measure resistance between engine coolant
(194°F)?
FU(SOHCw/
ture sensor. <Ref.
temperature sensor terminals.
oOBD)-38, Engine
to FU(SOHCw/
Terminals
Control Module.>
oOBD)-23, Engine
No. 1 - No. 2:
Coolant Tempera-
ture Sensor.>
EN(SOHCw/oOBD)-72
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics) MEMO:
EN(SOHCw/oOBD)-73
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
C: DTC 22 KNOCK SENSOR S06
•  DIAGNOSIS:
•  The knock sensor signal is abnormal.
•  The harness connector between ECM and knock sensor is in short or open.
•  TROUBLE SYMPTOM:
•   Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-375.jpg
EN(SOHCw/oOBD)-74
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK HARNESS BETWEEN KNOCK SENSOR AND ECM CONNECTOR.
1) Turn ignition switch to OFF. 2) Disconnect connector from ECM. 3) Measure resistance of harness between ECM connector and engine ground. Connector & terminal (E22) No. 16 - Engine ground:
Is the resistance more than 700 ??
Go to step 3.
Go to step 2.
2
CHECK HARNESS BETWEEN KNOCK SENSOR AND ECM CONNECTOR.
Measure resistance of harness between ECM connector and engine ground. Connector & terminal (E22) No. 16 - Engine ground:
Is the resistance less than 400 ??
Go to step 5.
Go to step 6.
3
CHECK KNOCK SENSOR.
1) Disconnect connector from knock sensor. 2) Measure resistance between knock sensor connector terminal and engine ground. Terminal No. 2 - Engine ground:
Is the resistance more than 700 ??
Go to step 4.
Repair harness and connector. NOTE: In this case, repair the follow­ing: • Open circuit in harness between knock sensor and ECM connector • Poor contact in knock sensor con­nector
4
CHECK CONDITION OF KNOCK SENSOR INSTALLATION.
Is the knock sensor instal­lation bolt tightened securely?
Replace knock sensor. <Ref. to FU(SOHCw/ oOBD)-25, Knock Sensor.>
Tighten knock sensor installation bolt securely.
5
CHECK KNOCK SENSOR.
1) Disconnect connector from knock sensor. 2) Measure resistance between knock sensor connector terminal and engine ground. Terminal No. 2 - Engine ground:
Is the resistance less than 400 ??
Replace knock sensor.
Repair ground short circuit in harness between knock sensor con­nector and ECM connector. NOTE: The harness between both connectors is shielded. Repair short circuit of harness together with shield.
EN(SOHCw/oOBD)-75
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
6
CHECK INPUT SIGNAL FOR ECM.
Is the voltage more than 2
Even if MIL lights
Repair poor con-
1) Connect ST. <Ref. to EN(SOHCw/oOBD)-
V?
up, the circuit has
tact in ECM con-
23, HOW TO CHECK I/O SIGNAL FOR ECM,
returned to a nor-
nector.
Engine Control Module (ECM) I/O Signal.>
mal condition at
ST 498307600 CHECK BOARD KIT
this time.
2) Turn ignition switch to ON.
(However, the
3) Measure voltage between ECM and engine
possibility of poor
ground.
contact still
Connector & terminal
remains.)
(B) No. 17 (+) - Engine ground (-):
NOTE:
In this case,
repair the follow-
ing:
• Poor contact in
knock sensor con-
nector
• Poor contact in
ECM connector
EN(SOHCw/oOBD)-76
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics) MEMO:
EN(SOHCw/oOBD)-77
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
D: DTC 45 PRESSURE SENSOR
S068521G67
•  DIAGNOSIS:
•  The pressure sensor signal is abnormal.
•  The harness connector between ECM and pressure sensor is in short or open.
•  TROUBLE SYMPTOM:
•   Erroneous idling
•   Engine stalls.
•   Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-376.jpg
EN(SOHCw/oOBD)-78
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK HARNESS BETWEEN ECM AND PRESSURE SENSOR CONNECTOR.
1) Disconnect connector from pressure sen­sor. 2) Turn ignition switch to ON. 3) Measure voltage between pressure sensor connector and engine ground. Connector & terminal (E21) No. 3 (+) - Engine ground (-):
Is the voltage between 4.5 V and 5.5 V?
Go to step 2.
Repair open cir­cuit in harness between ECM and pressure sen­sor.
2
CHECK HARNESS BETWEEN ECM AND PRESSURE SENSOR CONNECTOR.
1) Disconnect connector from ECM. 2) Measure resistance of harness between ECM and pressure sensor connector. Connector & terminal (E22) No. 22 - (E21) No. 2: (E22) No. 25 - (E21) No. 3: (E22) No. 18 - (E21) No. 1:
Is the resistance less than 1 Q?
Go to step 3.
Repair open cir­cuit in harness between ECM and pressure sen­sor connector.
3
CHECK HARNESS BETWEEN ECM AND PRESSURE SENSOR CONNECTOR. Measure resistance of harness between ECM connector and engine ground. Connector & terminal (E22) No. 25 - Engine ground: (E22) No. 18 - Engine ground: (E22) No. 22 - Engine ground:
Is the resistance more than 1 MQ?
Go to step 4.
Repair ground short circuit in harness between ECM and pres­sure sensor con­nector.
4
CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to OFF. 2) Disconnect connector from ECM, then con­nect ST. <Ref. to EN(SOHCw/oOBD)-23, HOW TO CHECK I/O SIGNAL FOR ECM, Engine Control Module (ECM) I/O Signal.> ST 498307600 CHECK BOARD KIT 3) Turn ignition switch to ON. 4) Measure voltage between ECM and engine ground. Connector & terminal (A) No. 15 (+) - Engine ground (-):
Is the voltage between 2.3 V and 2.5 V?
Go to step 5.
Replace pressure sensor. <Ref. to FU(SOHCw/ oOBD)-29, Pres­sure Sensor.>
5
CHECK INPUT SIGNAL FOR ECM.
1) Start engine, and idle it. 2) Measure voltage between ECM and engine ground. Connector & terminal (A) No. 15 (+) - Engine ground (-):
Is the voltage between 1.2 Vand 1.8 V?
Go to step 6.
Replace pressure sensor. <Ref. to FU(SOHCw/ oOBD)-29, Pres­sure Sensor.>
6
CHECK POOR CONTACT.
Check poor contact in pressure sensor con­nector.
Is there poor contact in pressure sensor connec­tor?
Repair poor con­tact in pressure sensor connector.
Replace pressure sensor. <Ref. to FU(SOHCw/ oOBD)-29, Pres­sure Sensor.>
EN(SOHCw/oOBD)-79
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
E: DTC 24 IDLE AIR CONTROL SOLENOID VALVE
S068521G60
•  DIAGNOSIS:
•  The idle air control solenoid valve is not in function.
•  The harness connector between ECM and idle air control solenoid valve is in short or open.
•  TROUBLE SYMPTOM:
•   Erroneous idling
•   Hard to start
•   Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-377.jpg
EN(SOHCw/oOBD)-80
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK AIR INTAKE SYSTEM.
Is there a fault in air intake
Repair or replace
Go to step 2.
1) Turn ignition switch to ON.
system?
air intake system.
2) Start engine and idle it.
3) Check the following item.
• Loose installation of intake manifold, idle air
control solenoid valve and throttle body
• Cracks of intake manifold gasket, idle air
control solenoid valve gasket and throttle
body gasket
• Loose control connection and cracks of idle
air control solenoid valve by-pass hose
• Disconnection of vacuum hoses
2
CHECK HARNESS BETWEEN ECM AND
Is the resistance less than
Go to step 3.
Repair open cir-
IDLE AIR CONTROL SOLENOID VALVE
1 Q?
cuit in harness
CONNECTOR.
between ECM
1) Turn ignition switch to OFF.
and idle air con-
2) Disconnect connector from ECM and idle
trol solenoid valve
air control solenoid valve.
connector.
3) Measure resistance of harness between
ECM and idle air control solenoid valve con-
nector.
Connector & terminal
(E22) No. 4 - (E7) No. 1:
3
CHECK HARNESS BETWEEN ECM AND
Is the resistance less than
Go to step 4.
Repair open cir-
IDLE AIR CONTROL SOLENOID VALVE
1 Q?
cuit in harness
CONNECTOR.
between ECM
Measure resistance of harness between ECM
and idle air con-
and idle air control solenoid valve connector.
trol solenoid valve
Connector & terminal
connector.
(E22) No. 11 - (E7) No. 3:
4
CHECK HARNESS BETWEEN ECM AND
Is the resistance more than
Repair ground
Go to step 5.
IDLE AIR CONTROL SOLENOID VALVE
1 MQ?
short in harness
CONNECTOR.
between ECM
Measure resistance of harness between ECM
and idle air con-
connector and engine ground.
trol solenoid
Connector & terminal
valve.
(E22) No. 11 - Engine ground:
5
CHECK HARNESS BETWEEN ECM AND
Is the resistance more than
Repair ground
Go to step 6.
IDLE AIR CONTROL SOLENOID VALVE
1 MQ?
short circuit in
CONNECTOR.
harness between
Measure resistance of harness between ECM
ECM and idle air
connector and engine ground.
control solenoid
Connector & terminal
valve connector.
(E22) No. 4 - Engine ground:
6
CHECK POOR CONTACT.
Is there poor contact in
Repair poor con-
Go to step 7.
Check poor contact in ECM connector.
ECM connector?
tact in ECM con-
nector.
7
CHECK MAIN RELAY.
Is the resistance less than
Go to step 8.
Replace main
1) Turn ignition switch to OFF.
10 Q?
relay.
2) Remove main relay.
3) Connect battery to main relay terminals No.
1 and No. 2.
4) Measure resistance between main relay
terminals.
Terminals
No. 4 - No. 6:
EN(SOHCw/oOBD)-81
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
8
CHECK POWER SUPPLY TO IDLE AIR
Is the voltage more than 10
Go to step 9.
Repair harness
CONTROL SOLENOID VALVE.
V?
and connector.
1) Disconnect connector from idle air control
NOTE:
solenoid valve.
In this case,
2) Turn ignition switch to ON.
repair the follow-
3) Measure voltage between idle air control
ing:
solenoid valve connector and engine ground.
• Open circuit in
Connector & terminal
harness between
(E7) No. 2 (+) - Engine ground (-):
idle air control
solenoid valve
and battery
• Poor contact in
coupling connec-
tor (B20)
9
CHECK POOR CONTACT.
Is there poor contact in idle
Repair poor con-
Contact your
Check poor contact in idle air control solenoid
air control solenoid valve
tact in idle air
Subaru distributor.
valve connector.
connector?
control solenoid
NOTE:
valve connector.
Inspection by your
Subaru distributor
is required,
because probable
cause is deterio-
ration of multiple
parts.
EN(SOHCw/oOBD)-82
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics) MEMO:
EN(SOHCw/oOBD)-83
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
F: DTC 26 INTAKE AIR TEMPERATURE SENSOR
S068521G61
•  DIAGNOSIS:
•  The intake air temperature sensor signal is abnormal.
•  The harness connector between ECM and intake air temperature sensor is in short or open.
•  TROUBLE SYMPTOM:
•   Hard to start
•   Erroneous idling
•   Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-378.jpg
EN(SOHCw/oOBD)-84
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK INTAKE AIR TEMPERATURE SEN-
Is the resistance between 2
Go to step 2.
Replace intake air
SOR.
and 3 kQ at 20°C (68°F)?
temperature sen-
1) Turn ignition switch to OFF.
sor. <Ref. to
2) Disconnect connector from intake air tem-
FU(SOHCw/
perature sensor.
oOBD)-30, Intake
3) Measure resistance between intake air
Air Temperature
temperature sensor terminals.
Sensor.>
Terminals
No. 1 - No. 2:
2
CHECK INTAKE AIR TEMPERATURE SEN-
Is the resistance between 2
Go to step 3.
Replace intake air
SOR.
and 3 kQat50°C(122°F)?
temperature sen-
Measure resistance between intake air tem-
sor. <Ref. to
perature sensor terminals.
FU(SOHCw/
Terminals
oOBD)-30, Intake
No. 1 - No. 2:
Air Temperature
Sensor.>
3
CHECK HARNESS BETWEEN ECM AND
Is the resistance less than
Go to step 4.
Repair open cir-
INTAKE AIR TEMPERATURE SENSOR
1 Q?
cuit in harness
CONNECTOR.
between ECM
1) Disconnect connector from ECM.
and intake air
2) Measure resistance of harness connector
temperature sen-
between ECM and intake air temperature sen-
sor connector.
sor connector.
Connector & terminal
(E22) No. 17 - (E20) No. 1:
(E22) No. 22 - (E20) No. 2:
4
CHECK HARNESS BETWEEN ECM AND
Is the resistance more than
Go to step 5.
Repair ground
INTAKE AIR TEMPERATURE SENSOR
1 MQ?
short circuit in
CONNECTOR.
harness between
Measure resistance of harness between ECM
ECM and idle air
connector and engine ground.
control solenoid
Connector & terminal
valve connector.
(E22) No. 17 - Engine ground:
(E22) No. 22 - Engine ground:
5
CHECK POOR CONTACT.
Is there poor contact in
Repair poor con-
Contact your
Check poor contact in ECM connector.
ECM connector?
tact in ECM con-
Subaru distributor.
nector.
NOTE:
Inspection by your
Subaru distributor
is required,
because probable
cause is deterio-
ration of multiple
parts.
EN(SOHCw/oOBD)-85
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
G: DTC 31 THROTTLE POSITION SENSOR
S068521G62
•  DIAGNOSIS:
•  The throttle position sensor signal is abnormal.
•  The throttle position sensor is installed abnormally.
•  The harness connector between ECM and throttle position sensor is in short or open.
•  TROUBLE SYMPTOM:
•   Erroneous idling
•   Engine stalls
•   Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-379.jpg
EN(SOHCw/oOBD)-86
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to OFF. 2) Disconnect connector from ECM, then con­nect ST. <Ref. to EN(SOHCw/oOBD)-23, HOW TO CHECK I/O SIGNAL FOR ECM, Engine Control Module (ECM) I/O Signal.> ST 498307600 CHECK BOARD KIT 3) Turn ignition switch to ON. 4) Measure voltage between ECM and engine ground while throttle valve is fully closed. Connector & terminal (B) No. 23 (+) - Engine ground (-):
Is the voltage more than 4.5 V?
Go to step 3.
Go to step 2.
2
CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM and engine ground. Connector & terminal (B) No. 23 (+) - Engine ground (-):
Does the voltage change more than 4.5 V by shaking harness and connector of ECM while monitoring the value with voltage meter?
Repair poor con­tact in ECM con­nector.
Contact your Subaru distributor. NOTE: Inspection by your Subaru distributor is required, because probable cause is deterio­ration of multiple parts.
3
CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM connector and engine ground. Connector & terminal (B) No. 24 (+) - Engine ground (-):
Is the voltage less than 0.1 V?
Go to step 4.
Repair poor con­tact in ECM con­nector.
4
CHECK HARNESS BETWEEN ECM AND THROTTLE POSITION SENSOR CONNEC­TOR.
1) Turn ignition switch to OFF. 2) Disconnect connectors from throttle posi­tion sensor. 3) Turn ignition switch to ON. 4) Measure voltage between throttle position sensor connector and engine ground. Connector & terminal (E13) No. 3 (+) - Engine ground (-):
Is the voltage more than 4.5 V?
Go to step 5.
Repair harness and connector. NOTE: In this case, repair the follow­ing: • Open circuit in harness between throttle position sensor and ECM connector • Poor contact in throttle position sensor connector • Poor contact in ECM connector
5
CHECK HARNESS BETWEEN ECM AND THROTTLE POSITION SENSOR CONNEC­TOR.
1) Turn ignition switch to OFF. 2) Disconnect ECM connector from CHECK BOARD. 3) Measure resistance of harness between ECM and throttle position sensor connector. Connector & terminal (E22) No. 22 - (E13) No. 2:
Is the resistance less than 1 Q?
Go to step 6.
Repair harness and connector. NOTE: In this case, repair the follow­ing: • Open circuit in harness between throttle position sensor and ECM connector • Poor contact in ECM connector • Poor contact in throttle position sensor connector
EN(SOHCw/oOBD)-87
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
6
CHECK HARNESS BETWEEN ECM AND
Is the resistance less than
Repair ground
Go to step 7.
THROTTLE POSITION SENSOR CONNEC-
10 Q?
short circuit in
TOR.
harness between
Measure resistance of harness between
throttle position
throttle position sensor connector and engine
sensor and ECM
ground.
connector.
Connector & terminal
(E13) No. 2 - Engine ground:
7
CHECK POOR CONTACT.
Is there poor contact in
Repair poor con-
Go to step 8.
Check poor contact in throttle position sensor
throttle position sensor con-
tact in throttle
connector.
nector?
position sensor
connector.
8
CHECK CONDITION OF THROTTLE POSI-
Are the throttle position
Replace throttle
Adjust throttle
TION SENSOR INSTALLATION.
sensor installing screws
position sensor.
position sensor
tightened securely?
and tighten
throttle position
sensor installing
screws securely.
EN(SOHCw/oOBD)-88
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics) MEMO:
EN(SOHCw/oOBD)-89
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
H: DTC 32 OXYGEN SENSOR
S068521G63
•  DIAGNOSIS:
•  The oxygen sensor is not in function.
•  The harness connector between ECM and oxygen sensor is in short or open.
•  TROUBLE SYMPTOM:
•   Failure of engine to start
•   Erroneous idling
•   Poor driving performance
•   Engine stalls.
•   Idle mixture is out of specifications.
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-380.jpg
EN(SOHCw/oOBD)-90
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK FOR OTHER CAUSES AFFECTING EXHAUST GAS.
NOTE: • Check for use of improper fuel. • Check if engine oil or coolant level is extremely low.
Is CO% more than 2% after engine warm-up?
Check fuel sys­tem.
Go to step 2.
2
CHECK EXHAUST SYSTEM.
Is there a fault in exhaust system?
Repair exhaust system. NOTE: • Loose installa­tion of front por­tion of exhaust pipe onto cylinder heads • Loose connec­tion between front exhaust pipe and front catalytic con­verter • Damage of exhaust pipe resulting in hole
Go to step 3.
3
CHECK HARNESS BETWEEN OXYGEN SENSOR AND ECM CONNECTOR.
1) Turn ignition switch to OFF. 2) Disconnect connector from oxygen sensor. 3) Turn ignition switch to ON. 4) Measure voltage between front oxygen sensor harness connector and engine ground. Connector & terminal (B18) No. 4 (+) - Engine ground (-):
Is the voltage more than 0.2 V?
Go to step 4.
Repair harness and connector. NOTE: In this case, repair the follow­ing: • Open circuit in harness between ECM and oxygen sensor connector • Poor contact in the ECM connec­tor
4
CHECK POOR CONTACT.
Check poor contact in oxygen sensor connect tor.
Is there poor contact in oxygen sensor connector?
Repair poor con­tact in oxygen sensor connector.
Go to step 5.
5
CHECK MAIN RELAY.
1) Turn ignition switch to OFF. 2) Remove main relay. 3) Connect battery to main relay terminals No. 1 and No. 2. 4) Measure resistance between main relay terminals. Terminals No. 4 - No. 6:
Is the resistance less than 10 Q?
Go to step 6.
Replace main relay.
EN(SOHCw/oOBD)-91
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
6
CHECK POWER SUPPLY TO OXYGEN
Is the voltage more than 10
Go to step 7.
Repair power sup-
SENSOR.
V?
ply line.
1) Turn ignition switch to ON.
NOTE:
2) Measure voltage between oxygen sensor
In this case,
connector.
repair the follow-
Connector & terminal
ing:
(B18) No. 2 (+) - Engine ground (-):
• Open circuit in
harness between
battery and oxy-
gen sensor con-
nector
• Poor contact in
oxygen sensor
connector
• Poor contact in
main relay con-
nector
7
CHECK OXYGEN SENSOR.
Is the resistance less than
Repair poor con-
Replace oxygen
1) Turn ignition switch to OFF.
30 Q?
tact.
sensor. <Ref. to
2) Measure resistance between oxygen sen-
NOTE:
FU(SOHCw/
sor terminals.
In this case,
oOBD)-36, Oxy-
Terminals
repair the follow-
gen Sensor.>
No. 1 - No. 2:
ing:
• Poor contact in
ECM connector
• Poor contact in
oxygen sensor
connector
EN(SOHCw/oOBD)-92
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics) MEMO:
EN(SOHCw/oOBD)-93
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
I: DTC 33 VEHICLE SPEED SIGNAL S06
•  DIAGNOSIS:
•  The vehicle speed signal is abnormal.
•  The harness connector between ECM and vehicle speed sensor is in short or open.
•  TROUBLE SYMPTOM:
•   Erroneous idling
•   Engine stalls.
•   Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-381.jpg
EN(SOHCw/oOBD)-94
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK SPEEDOMETER OPERATION IN COMBINATION METER.
Does speedometer operate normally?
Go to step 2.
Check speedom­eter and vehicle speed sensor. <Ref. to IDI-7, INSPECTION, Combination Meter System.>
2
CHECK INPUT SIGNAL FOR ECM.
1) Disconnect connector from ECM, then con­nect ST. <Ref. to EN(SOHCw/oOBD)-23, HOW TO CHECK I/O SIGNAL FOR ECM, Engine Control Module (ECM) I/O Signal.> ST 498307600 CHECK BOARD KIT 2) Lift-up the vehicle. 3) Set the positive (+) terminal and earth lead of the oscilloscope at ECM connector termi­nals. Connector & terminal (D) No. 53 - Engine ground: 4) Start the engine. 5) Shift the gear position, and travel at a con­stant speed. 6) Measure the signal voltage indicated on the oscilloscope.
Is the voltage more than 3 V?
Go to step 3.
Go to step 4.
3
CHECK POOR CONTACT.
Check for poor contact at ECM connector.
Is there poor contact at the ECM connector?
Repair poor con­tact at ECM.
Replace ECM. <Ref. to FU(SOHCw/ oOBD)-38, Engine Control Module.>
4
CHECK HARNESS BETWEEN ECM AND COMBINATION METER CONNECTOR. Measure voltage between ECM and engine ground. Connector & terminal (D) No. 53 (+) - Engine ground (-):
Is the voltage more than 2 V?
Repair harness and connector. NOTE: In this case, repair the follow­ing: • Battery short circuit in harness between ECM and combination meter connector
Go to step 5.
5
CHECK HARNESS BETWEEN ECM AND COMBINATION METER CONNECTOR.
1) Turn ignition switch to OFF. 2) Disconnect check board. 3) Measure resistance of harness between ECM connector and engine ground. Connector & terminal (B84) No. 33 - Engine ground:
Is the resistance less than 10 Q?
Repair ground short circuit in harness between ECM and combi­nation meter con­nector.
Go to step 6.
6
CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
Repair poor con­tact in ECM.
Replace ECM. <Ref. to FU(SOHCw/ oOBD)-38, Engine Control Module.>
EN(SOHCw/oOBD)-95
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
J: DTC 35 PURGE CONTROL SOLENOID VALVE S06
•  DIAGNOSIS:
•  The purge control solenoid valve is not in function.
•  The harness connector between ECM and purge control solenoid valve is in short or open.
•  TROUBLE SYMPTOM:
•   Erroneous idling
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-382.jpg
EN(SOHCw/oOBD)-96
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK OPERATION SOUND OF PURGE
Does purge control sole-
Go to step 2.
Go to step 3.
CONTROL SOLENOID VALVE.
noid valve produce operat-
1) Turn ignition switch to OFF.
ing sound?
2) Connect test mode connector.
3) Turn ignition switch to ON.
4) Make sure that the ON/OFF operating
sound of purge control solenoid valve occurs
at about 10 Hz.
2
CHECK POOR CONTACT.
Is there poor contact in
Repair poor con-
Replace ECM.
Check poor contact in ECM connector.
ECM connector?
tact in ECM.
<Ref. to
FU(SOHCw/
oOBD)-38, Engine
Control Module.>
3
CHECK HARNESS BETWEEN PURGE
Is the voltage more than 10
Repair battery
Go to step 4.
CONTROL SOLENOID VALVE AND ECM
V?
short circuit in
CONNECTOR.
harness between
1) Turn ignition switch to OFF.
ECM and purge
2) Disconnect test mode connector.
control solenoid
3) Disconnect connector from ECM, then con-
valve connector.
nect ST. <Ref. to EN(SOHCw/oOBD)-23,
After repair,
HOW TO CHECK I/O SIGNAL FOR ECM,
replace ECM.
Engine Control Module (ECM) I/O Signal.>
ST 498307600 CHECK BOARD KIT
4) Disconnect connector from purge control
solenoid valve.
5) Turn ignition switch to ON.
6) Measure voltage between ECM and engine
ground.
Connector & terminal
(A) No. 3 (+) - Engine ground (-):
4
CHECK HARNESS BETWEEN PURGE
Is the resistance less than
Go to step 5.
Repair open cir-
CONTROL SOLENOID VALVE AND ECM
1 Q?
cuit in harness
CONNECTOR.
between ECM
1) Turn ignition switch to OFF.
and purge control
2) Disconnect ECM connector from CHECK
solenoid valve
BOARD.
connector.
3) Measure resistance of harness between
ECM and purge control solenoid valve of har-
ness connector.
Connector & terminal
(E22) No. 5 - (E4) No. 2:
5
CHECK PURGE CONTROL SOLENOID
Is the resistance between
Go to step 6.
Replace purge
VALVE.
23 and 27 Q?
control solenoid
1) Remove purge control solenoid valve.
valve. <Ref. to
2) Measure resistance between purge control
EC(SOHCw/
solenoid valve terminals.
oOBD)-7, Purge
Terminal
Control Solenoid
No. 1 - No. 2:
Valve. >
6
CHECK MAIN RELAY.
Is the resistance less than
Go to step 7.
Replace main
1) Turn ignition switch to OFF.
10 Q?
relay.
2) Remove main relay.
3) Connect battery to main relay terminals No.
1 and No. 2.
4) Measure resistance between main relay
terminals.
Terminals
No. 4 - No. 6:
EN(SOHCw/oOBD)-97
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
7
CHECK POWER SUPPLY TO PURGE CON­TROL SOLENOID VALVE.
1) Turn ignition switch to ON. 2) Measure voltage between purge control solenoid valve and engine ground. Connector & terminal (E4) No. 1 (+) - Engine ground (-):
Is the voltage more than 10 V?
Go to step 8.
Repair harness and connector. NOTE: In this case, repair the follow­ing: • Open circuit in harness between battery and purge control solenoid valve connector • Poor contact in main relay con­nector • Poor contact in coupling connec­tor (B20)
8
CHECK POOR CONTACT.
Check poor contact in purge control solenoid valve connector.
Is there poor contact in purge control solenoid valve connector?
Repair poor con­tact in purge con­trol solenoid valve connector.
Contact your Subaru distributor. NOTE: Inspection by your Subaru distributor is required, because probable cause is deterio­ration of multiple parts.
EN(SOHCw/oOBD)-98
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics) MEMO:
EN(SOHCw/oOBD)-99
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
K: DTC 38 TORQUE CONTROL SIGNAL
S068521G66
•  DIAGNOSIS:
•  Abnormal signal entered from TCM
•  The harness connector between ECM and TCM is in short.
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-383.jpg
EN(SOHCw/oOBD)-100
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK HARNESS BETWEEN ECM AND
Is the resistance less than
Repair ground
Go to step 2.
TCM CONNECTOR.
10 Q?
short circuit in
1) Disconnect connectors from ECM and
harness between
TCM.
ECM and TCM
2) Measure resistance of harness between
connector.
ECM and engine ground.
Connector & terminal
(B84) No. 7 - Engine ground:
2
CHECK HARNESS BETWEEN ECM AND
Is there resistance less
Repair ground
Replace TCM.
TCM CONNECTOR.
than 10 Q?
short circuit in
<Ref. to AT-48
Measure resistance of harness between ECM
harness between
Transmission
and engine ground.
ECM and TCM
Control Module
Connector & terminal
connector.
(TCM).>
(B84) No. 18 - Engine ground:
EN(SOHCw/oOBD)-101
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
L: DTC 46 CO RESISTOR (GENERAL SPEC. VEHICLES) S06
•  DIAGNOSIS:
•  The CO resistor signal is abnormal.
•  The harness connector between ECM and CO resistor is in short or open.
•  The CO value is not adjusted to specifications.
•  TROUBLE SYMPTOM:
•   Erroneous idling
•  Mixture ratio is too rich or too lean.
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-384.jpg
EN(SOHCw/oOBD)-102
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK INPUT SIGNAL FOR ECM.
Is the voltage between 0.5
Go to step 3.
Go to step 2.
1) Turn ignition switch to OFF.
V and 4.5 V?
2) Disconnect connector from ECM, then con-
nect ST. <Ref. to EN(SOHCw/oOBD)-23,
HOW TO CHECK I/O SIGNAL FOR ECM,
Engine Control Module (ECM) I/O Signal.>
ST 498307600 CHECK BOARD KIT
3) Turn ignition switch to ON.
4) Measure voltage between ECM and engine
ground.
Connector & terminal
(D) No. 56 (+) - Engine ground (-):
2
CHECK POOR CONTACT.
Is there poor contact in
Repair poor con-
Replace ECM.
ECM connector?
tact in ECM con-
<Ref. to
nector.
FU(SOHCw/
oOBD)-38, Engine
Control Module.>
3
CHECK HARNESS BETWEEN CO RESIS-
Is the resistance less than
Go to step 4.
Repair open cir-
TOR AND ECM CONNECTOR.
1 Q?
cuit in harness
1) Turn ignition switch to OFF.
between ECM
2) Disconnect connector from ECM and CO
and CO resistor
resistor.
connector.
3) Measure resistance of harness between
ECM and CO resistor connector.
Connector & terminal
(B84) No. 1 - (B155) No. 3:
(B84) No. 30 - (B155) No. 2:
(B84) No. 15 - (B155) No. 1:
4
CHECK HARNESS BETWEEN CO RESIS-
Is the resistance more than
Go to step 5.
Repair short cir-
TOR AND ECM CONNECTOR.
1 MQ?
cuit in harness
Measure resistance of harness between ECM
between ECM
connector and engine ground.
and CO resistor
Connector & terminal
connector.
(B84) No. 1 - Engine ground:
(B84) No. 30 - Engine ground:
(B84) No. 15 - Engine ground:
5
CHECK CO RESISTOR.
Is the resistance between 4
Go to step 6.
Replace CO resis-
Measure resistance between CO resistor ter-
and 6 kQ?
tor.
minals.
Terminals
No. 1 - No. 3:
6
CHECK CO RESISTOR.
Is the resistance between 0
Replace ECM.
Replace CO resis-
Measure variable resistance between CO
and 6 kQ?
tor.
resistor terminals while rotating the screw of
NOTE:
CO resistor.
Ensure resistance
Terminals
varies in response
No. 1 - No. 2:
to screw rotation.
EN(SOHCw/oOBD)-103
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
M: DTC 51 NEUTRAL POSITION SWITCH
S068521H58
•  DIAGNOSIS:
•  The neutral position switch signal is abnormal.
•  The harness connector between ECM and neutral position switch is in short or open.
•  TROUBLE SYMPTOM:
•   Erroneous idling
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
for_01_21-385.jpg
EN(SOHCw/oOBD)-104
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to OFF. 2) Disconnect connector from ECM, then con­nect ST. <Ref. to EN(SOHCw/oOBD)-23, HOW TO CHECK I/O SIGNAL FOR ECM, Engine Control Module (ECM) I/O Signal.> ST 498307600 CHECK BOARD KIT 3) Turn ignition switch to ON. 4) Measure voltage between ECM and engine ground. Connector & terminal (D) No. 60 (+) - Engine ground (-):
Is the voltage between 4.5 and 5.5 V in neutral posi­tion?
Go to step 2.
Go to step 4.
2
CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM and engine ground. Connector & terminal (D) No. 60 (+) - Engine ground (-):
Is the voltage less than 1 V in other positions?
Go to step 3.
Go to step 4.
3
CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
Repair poor con­tact in ECM con­nector.
Contact your Subaru distributor.
4
CHECK NEUTRAL POSITION SWITCH.
1) Turn ignition switch to OFF. 2) Disconnect connector from transmission harness. 3) Measure resistance between transmission harness and connector terminals. Connector & terminal (T2) No. 1 - No. 2:
Is the resistance more than 1 MQ in neutral position?
Go to step 5.
Repair short cir­cuit in transmis­sion harness or replace neutral position switch.
5
CHECK NEUTRAL POSITION SWITCH.
Measure resistance between transmission harness connector terminals. Connector & terminal (T2) No. 1 - No. 2:
Is the resistance less than 1 Q in other positions?
Go to step 6.
Repair open cir­cuit in transmis­sion harness or replace neutral position switch.
6
CHECK HARNESS BETWEEN ECM AND NEUTRAL POSITION SWITCH CONNEC­TOR.
1) Disconnect ECM connector from CHECK BOARD. 2) Measure resistance of harness between ECM and transmission harness connector. Connector & terminal (B84) No. 26 - (B25) No. 1:
Is the resistance less than 1 Q?
Go to step 7.
Repair open cir­cuit in harness between ECM and transmission harness connec­tor.
7
CHECK HARNESS BETWEEN ECM AND NEUTRAL POSITION SWITCH CONNEC­TOR.
Measure resistance between ECM connector and engine ground. Connector & terminal (B84) No. 26 - Engine ground:
Is the resistance less than 10 Q?
Repair ground short circuit in harness between ECM and trans­mission harness connector.
Go to step 8.
EN(SOHCw/oOBD)-105
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
8
CHECK NEUTRAL POSITION SWITCH GROUND CIRCUIT.
Measure resistance of harness between transmission harness connector and engine ground. Connector & terminal (B25) No. 2 - Engine ground:
Is the resistance less than 5Q?
Go to step 9.
Repair harness and connector. NOTE: In this case, repair the follow­ing: • Open circuit in harness between transmission har­ness connector and engine grounding termi­nal • Poor contact in coupling connec­tor (B138)
9
CHECK POOR CONTACT.
Check poor contact in transmission harness connector.
Is there poor contact in transmission harness con­nector?
Repair poor con­tact in transmis­sion harness con­nector.
Contact your Subaru distributor. NOTE: Inspection by your Subaru distributor is required, because probable cause is deterio­ration of multiple parts.
EN(SOHCw/oOBD)-106
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics) MEMO:
EN(SOHCw/oOBD)-107
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
S068521H59
N: DTC 54 - AIR INTAKE SYSTEM -
•  DIAGNOSIS:
•   Intake duct, hose, nipple, etc., looseness, displacement, detachment
•  TROUBLE SYMPTOM:
•   High idling revs
•   Poor engine pick up
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES.
<Ref. to EN(SOHCw/oOBD)-31, Clear Memory Mode.>, <Ref. to EN(SOHCw/oOBD)-29, Inspection
Mode.>
•  WIRING DIAGRAM:
for_01_21-386.jpg
EN(SOHCw/oOBD)-108
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK AIR INTAKE SYSTEM.
1) Turn ignition switch to ON. 2) Start engine, and idle it. 3) Check the following items: • Cracks of air intake duct • Disconnections of air intake duct • Check for looseness, displacement of the intake manifold. • Check that the intake manifold is connected in the instructed manner. (Gasket detachment, insufficient fastening torque of nuts and bolts) • Check for looseness, detachment of hose, nipple etc.
Is there a fault in the air intake system?
Repair or replace air intake system.
Go to step 2.
2
CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition to OFF. 2) Disconnect connector from ECM, then con­nect ST. <Ref. to EN(SOHCw/oOBD)-23, HOW TO CHECK I/O SIGNAL FOR ECM, Engine Control Module (ECM) I/O Signal.> ST 498307600 CHECK BOARD KIT 3) Turn ignition switch to ON. 4) Measure voltage between ECM and engine ground. Connector & terminal (D) No. 51 (+) - Engine ground (-):
Is the voltage between 3.4 V and 3.6 V?
Go to step 3.
Replace pressure sensor. <Ref. to FU(SOHCw/ oOBD)-29, Pres­sure Sensor.>
3
CHECK INPUT SIGNAL FOR ECM.
1) Start engine, and idle it. 2) Measure voltage between ECM and engine ground. Connector & terminal (D) No. 51 (+) - Engine ground (-):
Is the voltage between 1.2 Vand 1.8 V?
Go to step 4.
Replace pressure sensor. <Ref. to FU(SOHCw/ oOBD)-29, Pres­sure Sensor.>
4
CHECK INPUT SIGNAL FOR ECM.
1) Stop engine, and turn ignition switch to ON. 2) Measure voltage between ECM terminals while throttle valve is fully closed. Terminal No. 23 (+) - No. 21 (-):
Is the voltage between 0.2 Vand 1.0 V?
Go to step 5.
Replace throttle position sensor. <Ref. to FU(SOHCw/ oOBD)-26, Throttle Position Sensor.>
5
CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM terminals while throttle valve is fully opened. Terminal No. 23 (+) - No. 21 (-):
Is the voltage between 4.2 V and 4.7 V?
Go to step 6.
Replace throttle position sensor. <Ref. to FU(SOHCw/ oOBD)-26, Throttle Position Sensor.>
6
CHECK IDLE AIR CONTROL SOLENOID VALVE.
1) Start engine, and idle it. 2) Disconnect connector from idle air control solenoid valve.
Does engine revolution change?
Go to step 7.
Replace idle air control solenoid valve. <Ref. to FU(SOHCw/ oOBD)-31, Idle Air Control Solenoid Valve. >
EN(SOHCw/oOBD)-109
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
7
CHECK POOR CONTACT.
Is there poor contact in
Repair poor con-
Contact your
Check poor contact in ECM connector.
ECM connector?
tact in ECM con-
Subaru distributor.
nector.
NOTE:
Inspection by your
Subaru distributor
is required,
because probable
cause is deterio-
ration of multiple
parts.
EN(SOHCw/oOBD)-110
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
O: DTC 85 CHARGE SYSTEM
•  DIAGNOSIS:
•   Power source voltage of the ECM is low or high.
•  TROUBLE SYMPTOM:
•  Charge warning light comes on.
CAUTION:
After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES. <Ref. to EN(SOHCw/oOBD)-31 OPERATION, Clear Memory Mode.> and <Ref. to EN(SOHCw/ oOBD)-29 OPERATION, Inspection Mode.>
•  WIRING DIAGRAM:
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EN(SOHCw/oOBD)-111
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
Step
Check
Yes
No
1
CHECK GENERATOR.
1) Start engine. 2) Idling after warm-up. 3) Measure voltage between generator B ter­minal and chassis ground. Terminal Generator B terminal - Chassis ground:
Is the voltage between 10.8 Vand 16.2 V?
Go to step 2.
Repair generator. <Ref. to SC-12, Generator.>
2
CHECK GENERATOR.
1) Run the engine at 5,000 rpm. 2) Measure voltage between generator B ter­minal and chassis ground. Terminal Generator B terminal (+) - Chassis ground (-):
Is the voltage between 10.8 Vand 16.2 V?
Go to step 3.
Repair generator. <Ref. to SC-12, Generator.>
3
CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
Are the positive and nega­tive battery terminals tightly clamped?
Go to step 4.
Tighten the clamp of terminal.
4
CHECK INPUT VOLTAGE OF ECM.
1) Disconnect connector from ECM, then con­nect ST. <Ref. to EN(SOHCw/oOBD)-23, HOW TO CHECK I/O SIGNAL FOR ECM, Engine Control Module (ECM) I/O Signal.> ST 4983907600 CHECK BOARD KIT 2) Run the engine at idle. 3) Measure voltage between ECM connector and chassis ground. Connector & terminal (B) No. 27 (+) - Chassis ground (-): (C) No. 36 (+) - Chassis ground (-):
Is the voltage between 10.8 Vand 16.2 V?
Go to step 5.
Repair harness connector between battery, main relay and ECM.
5
CHECK POOR CONTACT IN CONNEC­TORS.
Is there poor contact in connectors between generator, battery and ECM?
Repair connector.
Go to step 6.
6
CHECK ECM.
1) Connect all connectors. 2) Erase the memory. 3) Perform inspection mode. 4) Read out the trouble code.
Is the same trouble code as in the current diagnosis still being output?
Replace genera­tor.
Go to step 7.
7
CHECK ANY OTHER TROUBLE CODES APPEARANCE.
Are other trouble codes being output?
Proceed with the diagnosis corre­sponding to the trouble code.
A temporary poor contact.
EN(SOHCw/oOBD)-112