Subaru 2009 IMPREZA Service Manual page 655

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 7 (+) — Chassis ground (–):
(B135) No. 2 (+) — Chassis ground (–):
2 CHECK INPUT VOLTAGE OF ECM.
1) Start the engine.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 7 (+) — Chassis ground (–):
(B135) No. 2 (+) — Chassis ground (–):
3 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
electronic throttle control.
3) Measure the resistance of harness between
ECM and electronic throttle control connector.
Connector & terminal
(B134) No. 19 — (E57) No. 5:
(B134) No. 29 — (E57) No. 3:
4 CHECK ECM GROUND HARNESS.
Measure the voltage between ECM and chassis
ground.
Connector & terminal
(B134) No. 5 (+) — Chassis ground (–):
(B137) No. 1 (+) — Chassis ground (–):
(B137) No. 2 (+) — Chassis ground (–):
(B137) No. 3 (+) — Chassis ground (–):
(B137) No. 7 (+) — Chassis ground (–):
CB:DTC P0638 THROTTLE ACTUATOR CONTROL RANGE/PERFORMANCE
(BANK 1)
NOTE:
For the diagnostic procedure, refer to DTC P2101. <Ref. to EN(H4SO)(diag)-282, DTC P2101 THROTTLE
ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>
CC:DTC P0700 TRANSMISSION CONTROL SYSTEM (MIL REQUEST)
NOTE:
For the diagnostic procedure, refer to AT section. <Ref. to 4AT(diag)-2, Basic Diagnostic Procedure.>
Check
Is the voltage 10 — 13 V?
Is the voltage 13 — 15 V?
Is the resistance less than 1 ? Go to step 4.
Is the voltage less than 1 V?
EN(H4SO)(diag)-238
Yes No
Go to step 2. Repair the open or
ground short circuit
of power supply
circuit.
Go to step 3. Repair the open or
ground short circuit
of power supply
circuit.
Repair the open
circuit of harness
between ECM and
electronic throttle
control connector.
Repair the poor Repair the follow-
contact of ECM ing item.
connector. • Open circuit in
ground circuit
• Further tighten-
ing of the engine
ground terminal
• Poor contact of
coupling connector