Subaru 2009 IMPREZA Service Manual page 2426

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ABS (DIAGNOSTICS)
Step
1 CHECK GENERATOR.
1) Start the engine.
2) Run the engine at idle after warming up.
3) Measure the voltage between generator ter-
minal B 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 ABSCM&H/U connectors.
2) Run the engine at idle.
3) Operate devices such as headlights, air
conditioner, defogger, etc. which produce an
electrical load.
4) Measure the voltage between ABSCM&H/U
connector and chassis ground.
Connector & terminal
(B301) No. 18 (+) — Chassis ground (–):
4 CHECK THE ABSCM&H/U GROUND CIR-
CUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between the
ABSCM&H/U connector and chassis ground.
Connector & terminal
(B301) No. 15 — Chassis ground:
5 CHECK POOR CONTACT OF CONNECTOR. Is there poor contact of connec-
6 CHECK ABSCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to ABS(diag)-21,
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to
ABS(diag)-20, Inspection Mode.>
4) Read the DTC.
7 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?
Check
Is the voltage 10 — 15 V?
Are the positive and negative
battery terminals tightened
securely?
Is the voltage 10 — 15 V?
Is the resistance less than 0.5 ? Go to step 5.
tor between generator, battery
and ABSCM&H/U?
Is the same DTC displayed?
ABS(diag)-46
Yes No
Go to step 2. Repair the genera-
tor.
Go to step 3. Tighten the termi-
nal.
Go to step 4. Repair the
ABSCM&H/U
power circuit.
Repair the
ABSCM&H/U
ground harness.
Repair the connec- Go to step 6.
tor.
Replace the Go to step 7.
ABSCM only. <Ref.
to ABS-8,
REPLACEMENT,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
Check DTC using Temporary poor
"List of Diagnostic contact occurs.
Trouble Code
(DTC)". <Ref. to
ABS(diag)-26, List
of Diagnostic Trou-
ble Code (DTC).>