Subaru 2009 IMPREZA, Service Manual

Page: 1469 / 3619

EN(H4DOTC)(diag)-248
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
CF:DTC P0638 THROTTLE ACTUATOR CONTROL RANGE/PERFORMANCE
(BANK 1)
NOTE:
For the diagnostic procedure, refer to DTC P2101. <Ref. to EN(H4DOTC)(diag)-319, DTC P2101 THROT-
TLE ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Di-
agnostic Trouble Code (DTC).>
CG:DTC P0700 TRANSMISSION CONTROL SYSTEM (MIL REQUEST)
NOTE:
For the diagnostic procedure, refer to AT section. <Ref. to 4AT(diag)-2, Basic Diagnostic Procedure.>
Step Check Yes No
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 (–):
Is the voltage 10 — 13 V? Go to step 2 . Repair the open or
ground short circuit
of power supply
circuit.
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 (–):
Is the voltage 13 — 15 V? Go to step 3 . Repair the open or
ground short circuit
of power supply
circuit.
3 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL CON-
NECTOR.
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:
Is the resistance less than 1
:
? Go to step 4 . Repair the open
circuit of harness
between ECM and
electronic throttle
control connector.
4 CHECK ECM GROUND HARNESS.
1) Connect all connectors.
2) Turn the ignition switch to ON.
3) 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 (–):
Is the voltage less than 1 V? Repair the poor
contact of ECM
connector. Repair the follow-
ing item.
• Open circuit in
ground circuit
• Further tighten-
ing of the engine
ground terminal
• Poor contact of
ECM connector
• Poor contact of
coupling connector