Antilock Brake Module (ABS)

C1200-16-BATTERY VOLTAGE - BELOW THRESHOLD





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
Ignition on.

- Set Condition:
If the sensed ignition voltage drops below 9 volts with engine running or vehicle speed present for 100 msec or if voltage is below 7 volts the maturation time changes to 15 ms.





1. VERIFY THE DTC IS ACTIVE

NOTE: Diagnose and repair any Powertrain Charging system DTCs before continuing with this procedure.

NOTE: Make sure the battery is fully charged.

1. Ignition on, engine not running.
2. With the scan tool, record and erase DTCs.
3. Turn ignition off to the lock position.
4. Start the engine.
5. With the scan tool, read DTCs.

Is the DTC active at this time?

Yes

- Go To 2

No

- Perform the ABS-INTERMITTENT CONDITION TEST. ABS Intermittent Condition Test.

2. POWER CIRCUITS FOR AN OPEN OR HIGH RESISTANCE




1. Turn ignition off to the lock position.
2. Disconnect the ABS Module harness connector.
3. Ignition on, engine not running.
4. With a 12-volt test light connected to ground, check the Fused B+ and Fused Ignition Switch Output circuits at the ABS Module harness connector.

Does the test light illuminate brightly?

Yes

- Go To 3

No

- Repair the Power circuits for an open or high resistance.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

3. GROUND CIRCUITS OPEN OR HIGH RESISTANCE




1. Turn ignition off to the lock position.
2. With a test light connected to B+ check the Ground circuits at the ABS Module harness connector.

Does the test light illuminate brightly?

Yes

- Replace the Anti-lock Brake System (ABS) Module. Anti-Lock Brake System Module - Removal.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

No

- Repair the Ground circuits for an open or high resistance.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.