Subaru Impreza 2003 Service Manual page 1721

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
6 CHECK HARNESS CONNECTOR BETWEEN
TCM AND THROTTLE POSITION SENSOR.
Measure the resistance of harness between
TCM and throttle position sensor connector.
Connector & terminal
SOHC MODEL
(B54) No. 2 — (E13) No. 4:
DOHC TURBO MODEL
(B54) No. 2 — (E13) No. 1:
7 CHECK HARNESS CONNECTOR BETWEEN
TCM AND THROTTLE POSITION SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 3 — Chassis ground:
8 CHECK HARNESS CONNECTOR BETWEEN
TCM AND THROTTLE POSITION SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 2 — Chassis ground:
9 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM and ECM connector.
Connector & terminal
SOHC MODEL
(B54) No. 3 — (B136) No. 17:
DOHC TURBO MODEL
(B54) No. 3 — (B135) No. 7:
10 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM and ECM connector.
Connector & terminal
SOHC MODEL
(B54) No. 2 — (B136) No. 15:
DOHC TURBO MODEL
(B54) No. 2 — (B135) No. 9:
11 PREPARE SUBARU SELECT MONITOR.
12 CHECK INPUT SIGNAL FOR TCM.
1)Connect the connectors to TCM, throttle
position sensor and ECM.
2)Turn the ignition switch to ON (engine OFF).
3)Close the throttle completely.
4)Measure the voltage between TCM connec-
tor and chassis ground.
Connector & terminal
(B54) No. 3 (+) — Chassis ground ( − − − − ):
13 CHECK INPUT SIGNAL FOR TCM.
1)Open the throttle completely and hold it.
2)Measure the voltage between TCM connec-
tor and chassis ground.
Connector & terminal
(B54) No. 3 (+) — Chassis ground ( − − − − ):
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Check
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is the resistance more than 1
MΩ?
Is the resistance less than 1
Ω?
Is the resistance less than 1
Ω?
Do you have a Subaru Select
Monitor?
Is the voltage 0.2 — 1.0 V?
Is the voltage 4.2 — 4.7 V?
4AT-51
Yes
Go to step 7. Repair the open
circuit in harness
between TCM and
throttle position
sensor connector,
and poor contact
in coupling con-
nector.
Go to step 8. Repair the short
circuit in harness
between TCM and
throttle position
sensor connector.
Go to step 9. Repair the short
circuit in harness
between TCM and
throttle position
sensor connector.
Go to step 10. Repair the open
circuit in harness
between TCM and
ECM connector.
Go to step 11. Repair the open
circuit in harness
between TCM and
ECM connector.
Go to step 14. Go to step 12.
Go to step 13. Go to step 18.
Go to step 16. Go to step 18.
No