Subaru FORESTER 2001 Service Manual page 246

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK CURRENT DATA.
1) Start engine.
2) Read data of exhaust gas temperature
sensor signal using Subaru Select Monitor or
OBD-II general scan tool.
NOTE:
¼ Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN(DOHC TURBO)-36, Subaru
Select Monitor.>
¼ OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.
2 CHECK HARNESS BETWEEN EXHAUST
GAS TEMPERATURE SENSOR AND ECM
CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from exhaust gas
temperature sensor.
3) Measure voltage between exhaust gas
temperature sensor connector and engine
ground.
Connector & terminal
(B279) No. 1 (+) — Engine ground (−):
3 CHECK HARNESS BETWEEN EXHAUST
GAS TEMPERATURE SENSOR AND ECM
CONNECTOR.
1) Turn ignition switch to ON.
2) Measure voltage between exhaust gas
temperature sensor connector and engine
ground.
Connector & terminal
(B279) No. 1 (+) — Engine ground (−):
4 CHECK HARNESS BETWEEN EXHAUST
GAS TEMPERATURE SENSOR AND ECM
CONNECTOR.
Measure voltage between exhaust gas tem-
perature sensor connector and engine
ground.
Connector & terminal
(B279) No. 1 (+) — Engine ground (−):
Step
Is the value less than
372°C (702°F)?
Is the voltage more than 10
V?
Is the voltage more than 10
V?
Is the voltage more than 4
V?
EN(DOHC TURBO)-245
Check Yes
Go to step 2.
Repair battery
short circuit in
harness between
ECM and exhaust
gas temperature
sensor connector.
Repair battery
short circuit in
harness between
ECM and exhaust
gas temperature
sensor connector.
Go to step 5.
Engine (Diagnostics)
No
Repair poor con-
tact.
NOTE:
In this case,
repair the follow-
ing:
¼ Poor contact in
exhaust gas tem-
perature sensor
¼ Poor contact in
ECM
¼ Poor contact in
joint connector
Go to step 3.
Go to step 4.
Repair harness
and connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
ECM and exhaust
gas temperature
sensor connector
¼ Poor contact in
exhaust gas tem-
perature sensor
connector
¼ Poor contact in
ECM connector
¼ Poor contact in
joint connector