Subaru Legacy Service Manual page 71

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ABS (DIAGNOSTICS)
Step
1 CHECK INPUT VOLTAGE OF ABSCM&H/U.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ABSCM&H/
U.
3) Run the engine at idle.
4) Measure the voltage between ABSCM&H/
U connector and chassis ground.
Connector & terminal
(B301) No. 18 (+) — Chassis ground (
(B301) No. 14 (+) — Chassis ground (
2 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
(B301) No. 15 — Chassis ground:
3 CHECK VALVE RELAY IN ABSCM&H/U.
Measure the resistance between ABSCM&H/U
terminals.
Terminals
No. 14 — No. 15:
4 CHECK POOR CONTACT IN CONNECTOR. Is there poor contact in con-
5 CHECK ABSCM&H/U.
1) Connect all the connectors.
2) Erase the memory.
3) Perform the inspection mode.
4) Read the DTC.
6 CHECK ANY OTHER DTC ON DISPLAY.
Check
Is the voltage 10 — 15 V?
−
):
−
):
Is the resistance less than 0.5
Ω?
Is the resistance more than 1
MΩ?
nector between generator, bat-
tery and ABSCM&H/U?
Is the same DTC displayed?
Is any other DTC displayed?
ABS(diag)-70
Yes
Go to step 2. Repair the har-
ness connector
between battery
and ABSCM&H/U.
Go to step 3. Repair the
ABSCM&H/U
ground harness.
Go to step 4. Replace the
ABSCM only.
<Ref. to ABS-8,
REPLACEMENT,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
Repair the con- Go to step 5.
nector.
Replace the Go to step 6.
ABSCM only.
<Ref. to ABS-8,
REPLACEMENT,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
Inspect the DTC Temporary poor
using "List of Diag- contact occurs.
nostic Trouble
Code (DTC)".
<Ref. to
ABS(diag)-39, List
of Diagnostic Trou-
ble Code (DTC).>
No