Subaru Impreza 2003 Service Manual page 2417

DIAGNOSTICS PROCEDURE WITHOUT DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK GENERATOR.
1)Start the engine.
2)Idle after warm-up.
3)Measure the voltage between generator B
terminal and chassis ground.
Terminals
Generator B terminal (+) — Chassis
ground ( − − − − ):
2 CHECK BATTERY TERMINAL.
Turn the ignition switch to OFF.
3 CHECK INPUT VOLTAGE OF ABSCM&H/U.
1)Disconnect the connector from ABSCM&
H/U.
2)Run the engine at idle.
3)Operate the electric load applying devices,
such as the headlight, A/C, and defogger.
4)Measure the voltage between ABSCM&H/U
connector and chassis ground.
Connector & terminal
LHD: (B301) No. 1 (+) — Chassis ground
( − − − − ):
RHD: (F49) No. 1 (+) — Chassis ground
( − − − − ):
4 CHECK GROUND CIRCUIT OF ABSCM&H/U.
1)Turn the ignition switch to OFF.
2)Measure the resistance between
ABSCM&H/U connector and chassis ground.
Connector & terminal
LHD: (B301) No. 23 — Chassis ground:
RHD: (F49) No. 23 — Chassis ground:
5 CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in con-
6 CHECK ABSCM&H/U.
1)Connect all connectors.
2)Erase the memory.
3)Perform the inspection mode.
4)Read out the DTC.
7 CHECK ANY OTHER DTC APPEARANCE.
Check
Is the voltage 10 — 17 V?
Are the positive and negative
battery terminals tightly
clamped?
Is the voltage 10 — 17 V?
Is the resistance less than 0.5
Ω?
nectors between generator,
battery and ABSCM&H/U?
Is the same DTC as in current
diagnosis still being output?
Are other DTCs being output? Proceed with the
ABS-77
ABS (DIAGNOSTICS)
Yes
Go to step 2. Repair the genera-
tor. <Ref. to
SC(H4SO)-14,
Generator.>
Go to step 3. Tighten the clamp
of terminal.
Go to step 4. Repair the power
supply circuit and
ABSCM&H/U.
Go to step 5. Repair the
ABSCM&H/U
ground harness.
Repair the con- Go to step 6.
nector.
Replace the Go to step 7.
ABSCM&H/U.
<Ref. to ABS-7,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
A temporary poor
diagnosis corre- contact.
sponding to DTC.
No