Subaru Legacy 2002 Service Manual page 896

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
No.
1 CHECK INTAKE AIR TEMPERATURE SEN-
SOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from intake air tem-
perature sensor.
3) Measure resistance between intake air
temperature sensor terminals.
Terminals
No. 2 — No. 3:
2 CHECK INTAKE AIR TEMPERATURE SEN-
SOR.
Measure resistance between intake air tem-
perature sensor terminals.
Terminals
No. 2 — No. 3:
3 CHECK HARNESS BETWEEN ECM AND
INTAKE AIR TEMPERATURE SENSOR
CONNECTOR.
1) Disconnect connector from ECM.
2) Measure resistance of harness connector
between ECM and intake air temperature sen-
sor connector.
Connector & terminal
(B136) No. 15 — (E20) No. 3:
4 CHECK HARNESS BETWEEN ECM AND
INTAKE AIR TEMPERATURE SENSOR
CONNECTOR.
Measure resistance of harness connector
between ECM and intake air temperature sen-
sor connector.
Connector & terminal
(B136) No. 13 — (E20) No. 2:
5 CHECK HARNESS BETWEEN ECM AND
INTAKE AIR TEMPERATURE SENSOR
CONNECTOR.
Measure resistance of harness between ECM
connector and chassis ground.
Connector & terminal
(B136) No. 15 — Chassis ground:
6 CHECK HARNESS BETWEEN ECM AND
INTAKE AIR TEMPERATURE SENSOR
CONNECTOR.
Measure resistance of harness between ECM
connector and chassis ground.
Connector & terminal
(B136) No. 13 — Chassis ground:
Step
Is the resistance between 2
and 3 kΩ at 20°C (68°F)?
Is the resistance between
0.66 and 1 kΩ at 50°C
(122°F)?
Is the resistance less than
1 Ω?
Is the resistance less than
1 Ω?
Is the resistance more than
1 MΩ?
Is the resistance more than
1 MΩ?
EN(w/oOBD)-85
Check Yes
Go to step 2.
Go to step 3.
Go to step 4.
Go to step 5.
Go to step 6.
Go to step 7.
Engine (Diagnostics)
No
Replace intake air
temperature sen-
sor. <Ref. to
FU(w/oOBD)-35,
Intake Air Tem-
perature and
Pressure Sensor.>
Replace intake air
temperature sen-
sor. <Ref. to
FU(w/oOBD)-35,
Intake Air Tem-
perature and
Pressure Sensor.>
Repair harness
and connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
ECM and intake
air temperature
and pressure sen-
sor connector
¼ Poor contact in
coupling connec-
tor (B21)
Repair harness
and connector.
Repair ground
short circuit in
harness between
ECM and idle air
control solenoid
valve connector.
Repair ground
short circuit in
harness between
ECM and idle air
control solenoid
valve connector.