Subaru FORESTER 2001 Service Manual page 126

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK CURRENT DATA.
1) Start engine.
2) Read data of intake air temperature sensor
signal using Subaru Select Monitor or the
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 procedure, refer to the
OBD-II General Scan Tool Instruction Manual.
2 CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from mass air flow
and intake air temperature sensor.
3) Turn ignition switch to ON.
4) Read data of intake air temperature sensor
signal using Subaru Select Monitor or the
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 procedure, refer to the
OBD-II General Scan Tool Instruction Manual.
Step
Is the value greater than
55°C (131°F)?
Is the value less than
−36°C (−33°F)?
EN(DOHC TURBO)-125
Check Yes
Go to step 2.
Replace mass air
flow and intake air
temperature sen-
sor. <Ref. to
FU(DOHC
TURBO)-34, Mass
Air Flow and
Intake Air Tem-
perature Sensor.>
Engine (Diagnostics)
No
Repair poor con-
tact.
NOTE:
In this case,
repair the follow-
ing:
¼ Poor contact
mass air flow and
intake air tem-
perature sensor
¼ Poor contact in
ECM
¼ Poor contact in
joint connector
Repair ground
short circuit in
harness between
mass air flow and
intake air tem-
perature sensor
and ECM connec-
tor.