Subaru Legacy 2004 Service Manual page 1439

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK BATTERY.
1) Turn the ignition switch to OFF.
2) Measure battery voltage and specific grav-
ity of electrolyte.
2 CHECK GENERATOR.
1) Start the engine.
2) Run the engine at idle after warming up.
3) Measure the voltage between generator B
terminal and chassis ground.
Terminals
Generator B terminal (+) — Chassis
"
ground ( ):
3 CHECK GENERATOR.
1) Run the engine at 5,000 rpm.
2) Measure the voltage between generator B
terminal and chassis ground.
Terminals
Generator B terminal (+) — Chassis
"
ground ( ):
4 CHECK BATTERY TERMINAL.
1) Turn the ignition switch to OFF.
2) Check the installation of positive and nega-
tive terminals of battery.
5 CHECK INPUT VOLTAGE OF ECM.
1) Run the engine at idle.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B135) No. 5 (+) — Chassis ground (
(B135) No. 6 (+) — Chassis ground (
6 CHECK POOR CONTACT IN CONNECTORS.
Check the poor contact in connectors between
generator, battery and ECM.
7 CHECK ECM.
1) Connect all the connectors.
2) Erase the memory. <Ref. to
EN(H4DOTC)(diag)-30, Clear Memory Mode.>
3) Perform the inspection mode. <Ref. to
EN(H4DOTC)(diag)-28, Inspection Mode.>
4) Read the DTC. <Ref. to
EN(H4DOTC)(diag)-27, Read Diagnostic Trou-
ble Code (DTC).>
Check if the same DTC is displayed.
8 CHECK ANY OTHER DTC IS DISPLAYED.
Check if any other DTC is displayed.
Check
Is the voltage more than 12 V
and the gravity more than
1.26?
Is the voltage more than 16.2
V?
Is the voltage more than 16.2
V?
Are the positive and negative
battery terminals clamped
tightly?
Is the voltage more than 16.2
V?
"
):
"
):
Is there poor contact in con-
nectors between generator,
battery and ECM?
Is the same DTC displayed?
Is any other DTC displayed?
EN(H4DOTC)(diag)-150
Yes
Go to step 2. Replace the bat-
tery.
Go to step 3. Repair the genera-
tor. <Ref. to
SC(H4SO 2.0)-14,
Generator.>
Go to step 4. Repair the genera-
tor. <Ref. to
SC(H4SO 2.0)-14,
Generator.>
Go to step 5. Tighten the clamp
of terminal.
Go to step 6. Repair the har-
ness connectors
between battery,
main relay and
ECM.
Repair the poor Go to step 7.
contact.
Replace the gen- Go to step 8.
erator.
Perform the diag- Temporary poor
nosis of DTC dis- contact occurs.
played.
No