Subaru Impreza 2003 Service Manual page 1732

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
H: DTC 45 INTAKE MANIFOLD PRESSURE SIGNAL (NON-TURBO MODEL)
DIAGNOSIS:
The input signal circuit of TCM from ECM is open or shorted.
TROUBLE SYMPTOM:
Excessive shift shock.
WIRING DIAGRAM:
B54
1 2 3 4 7 8
5 6
10 11 12 13 14 15 16 17 18
19 20 21 22 23 24
Step
1 CHECK ENGINE GROUND TERMINALS AND
GROUND CIRCUIT OF ECM
<Ref. to 4AT-48, DTC 31 THROTTLE POSI-
TION SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
1)Turn the ignition switch to OFF.
2)Disconnect the connectors from TCM and
ECM.
3)Measure the resistance of harness between
TCM and ECM connector.
Connector & terminal
SOHC WITHOUT OBD MODEL
(B54) No. 1 — (B136) No. 11:
SOHC WITH OBD MODEL
(B54) No. 1 — (B137) No. 2:
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 1 — Chassis ground:
B136
1 2 3
9
8 9 10 11 12 13 14 15
21 22 23 24 25
:
B136 OO ECM
:
WO
B137
B54 TCM
:
OO
6 7
4 5
16 17 18 19 20
26
27 28 29 30
Check
Is there any trouble?
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
4AT-62
: WITHOUT OBD
OO
WO
: WITH OBD
:
B137 WO
1 2 3 4
5 6 7 8 9 10 11 12 13
14 15 16 17 18 19 20
Yes
Repair the ground Go to step 2.
terminal and/or
ground circuit of
ECM.
Go to step 3. Repair the open
circuit in harness
between TCM and
ECM connector.
Go to step 4. Repair the short
circuit in harness
between TCM and
ECM connector.
AT-01147
No