Subaru Impreza 2003 Service Manual page 872

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK GENERATOR.
1)Start the engine.
2)Idle after warm-up.
3)Measure the voltage between generator B
terminal and chassis ground.
Terminal
Generator B terminal (+) — Chassis
ground (–):
2 CHECK GENERATOR.
1)Run the engine at 5,000 rpm.
2)Measure the voltage between generator B
terminal and chassis ground.
Terminal
Generator B terminal (+) — Chassis
ground ( − − − − ):
3 CHECK BATTERY TERMINAL.
Turn the ignition switch to OFF.
4 CHECK INPUT VOLTAGE OF ECM.
1)Run the engine at idle.
2)Measure the voltage between ECM connec-
tor and chassis ground.
Connector & terminal
(B136) No. 1 (+) — Chassis ground ( − − − − ):
(B136) No. 2 (+) — Chassis ground ( − − − − ):
5 CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in the
6 CHECK ECM.
1)Connect all connectors.
2)Erase the memory. <Ref. to EN(H4SOw/
oOBD)-28, OPERATION, Clear Memory
Mode.>
3)Perform the inspection mode. <Ref. to
EN(H4SOw/oOBD)-26, OPERATION, Inspec-
tion Mode.>
4)Read any DTC on the display. <Ref. to
EN(H4SOw/oOBD)-24, OPERATION, Read
Diagnostic Trouble Code (DTC).>
7 CHECK ANY OTHER DTCs APPEARANCE. Is any other DTC displayed?
Check
Is the voltage 10.8 V — 16.2
V?
Is the voltage 10.8 V — 16.2
V?
Are the positive and ground
battery terminals tightly
clamped?
Is the voltage 10.8 V — 16.2
V?
connectors between generator,
battery and ECM?
Is the same DTC as in the cur-
rent diagnosis still being out-
put?
EN(H4SOw/oOBD)-96
Yes
Go to step 2. Repair the genera-
tor. <Ref. to
SC(H4SO)-14,
Generator.>
Go to step 3. Repair the genera-
tor. <Ref. to
SC(H4SO)-14,
Generator.>
Go to step 4. Tighten the clamp
of terminal.
Go to step 5. Repair the har-
ness connector
between battery,
main relay and
ECM.
Repair the con- Go to step 6.
nector.
Replace the gen- Go to step 7.
erator.
Proceed with the A temporary poor
diagnosis corre- contact.
sponding to the
DTC.
No