Subaru Impreza 2003 Service Manual page 1720

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Step
1 CHECK ENGINE GROUND TERMINALS.
2 CHECK GROUND CIRCUIT OF ECM.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ECM.
3)Measure the resistance of harness between
ECM and engine ground.
Connector & terminal
SOHC MODEL WITH OBD
(B134) No. 7 — Engine ground:
(B134) No. 35 — Engine ground:
(B134) No. 7 — Engine ground:
(B135) No. 21 — Engine ground:
(B136) No. 5 — Engine ground:
(B136) No. 16 — Engine ground:
(B137) No. 14 — Engine ground:
SOHC MODEL WITHOUT OBD
(B134) No. 27 — Engine ground:
(B134) No. 8 — Engine ground:
(B134) No. 7 — Engine ground:
(B136) No. 21 — Engine ground:
(B136) No. 22 — Engine ground:
(B135) No. 6 — Engine ground: (RHD
MODEL)
DOHC TURBO MODEL
(B134) No. 7 — Engine ground:
(B134) No. 15 — Engine ground:
(B134) No. 22 — Engine ground:
(B137) No. 8 — Engine ground:
(B137) No. 17 — Engine ground:
(B137) No. 18 — Engine ground:
(B84) No. 8 — Engine ground:
(B84) No. 9 — Engine ground:
(B136) No. 1 — Engine ground:
3 CHECK THROTTLE POSITION SENSOR.
1)Disconnect the connector from throttle posi-
tion sensor.
2)Measure the resistance between throttle
position sensor connector receptacle's termi-
nals.
Terminals
SOHC MODEL
No. 4 — No. 2:
DOHC TURBO MODEL
No. 1 — No. 2:
4 CHECK THROTTLE POSITION SENSOR.
Measure the resistance between throttle posi-
tion sensor connector receptacle's terminals.
Terminals
No. 2 — No. 3:
5 CHECK HARNESS CONNECTOR BETWEEN
TCM AND THROTTLE POSITION SENSOR.
1)Disconnect the connector from TCM.
2)Measure the resistance of harness between
TCM and throttle position sensor connector.
Connector & terminal
(B55) No. 3 — (E13) No. 3:
Check
Have engine ground terminals
been tightened?
Is the resistance less than 5
Ω?
Is the resistance 3.0 — 4.2
kΩ?
Is the resistance 0.35 — 0.5
kΩ?
Is the resistance less than 1
Ω?
4AT-50
Yes
Go to step 2. Tighten the engine
ground terminals.
Go to step 3. Repair the open
circuit in harness
between ECM
connector and
engine grounding
terminal.
Go to step 4. Replace the throt-
tle position sensor.
Go to step 5. Replace the throt-
tle position sensor.
Go to step 6. Repair the open
circuit in harness
between TCM and
throttle position
sensor connector,
and poor contact
in coupling con-
nector.
No