Subaru IMPREZA 2004 Service Manual page 511

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
(B135) No. 1 (+) — Chassis ground ( − − − − ):
(B135) No. 2 (+) — Chassis ground ( − − − − ):
5 CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in con-
6 CHECK ECM.
1)Connect all connectors.
2)Erase the memory.
3)Perform the inspection mode.
4)Read out the DTC.
7 CHECK ANY OTHER DTC ON DISPLAY.
Check
Is the voltage less than 16.2
V?
Is the voltage less than 16.2
V?
Are the positive and ground
battery terminals tightly
clamped?
Is the voltage less than 16.2
V?
nectors between generator,
battery and ECM?
Is the same DTC as in the cur-
rent diagnosis still being out-
put?
Is any other DTC displayed?
EN(H4SO)(diag)-202
Yes
Go to step 2. Repair the genera-
tor. <Ref. to
SC(H4SO)-13,
Generator.>
Go to step 3. Repair the genera-
tor. <Ref. to
SC(H4SO)-13,
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. <Ref. to
SC(H4SO)-13,
Generator.>
Check the rele- A temporary poor
vant DTC using contact.
the List of Diag-
nostic Trouble
Code (DTC). <Ref.
to
EN(H4SO)(diag)-
74, List of Diag-
nostic Trouble
Code (DTC).>
No