D DTC C1115 Check ABS Relay

NOTE: Refer to the PINPOINT TEST section of the Flow of Diagnosis before beginning this pinpoint test. Flow of Diagnosis

NORMAL OPERATION:
The anti-lock brake control module conducts a valve function test every time the key is turned "ON" and the wheels exceed 6.4 km/in (4 mph) for the first time. In order to perform a valve function test, the anti-lock relay is commanded "ON" by the anti-lock brake control module to supply B+ to the valve solenoids and pump motor. The anti-lock relay is verified for proper operation by the anti-lock brake control module during this valve function test. A passive check of the anti-lock relay contacts is conducted by the anti-lock brake control module to check for shorted contacts during all times that the anti-lock relay is not commanded "ON" by the anti-lock brake control module.

FAULT DESCRIPTION:
A shorted anti-lock relay diagnostic trouble code (DTC) C1115 is generated by the anti-lock brake control module's detection of B+ from the pump motor feedback when it is expected to be low.

POSSIBLE CONTRIBUTING CONDITIONS:
- Shorted anti-lock brake relay.
- Defective circuit within the anti-lock brake control module.
- Short to B+ in the motor feedback circuit.

D1- Check Fault Repeatability
- Turn ignition switch to "OFF".
- Connect scan tool to Data Link Connector (DLC).
- Turn ignition switch to "RUN".
- Clear all DTC's using the scan tool.
- Perform the Drive Cycle Test. Refer To Inspection and Verification.
- Retrieve DTC's from ABS memory using the scan tool.
- Is DTC C1115 retrieved?
YES - Go to D2. If DTC C1095 is also retrieved, ignore.
NO - If a different DTC is retrieved, return to DTC Index.
- If only DTC C1095 is retrieved, Go to Pinpoint Test A.
- If a different DTC is retrieved, return to DTC Index.

D2- Check for a Short to B+
- Clear all DTC's using the scan tool.
- Turn ignition switch to "OFF".
- Disconnect connector from anti-lock relay.
- Perform the Drive Cycle Test. Refer To Inspection and Verification.
- Retrieve DTC's using the scan tool.
- Is C1115 retrieved?
YES - Go to D5.
NO - If a different DTC is retrieved, ignore and go to D3.

D3- Check Anti-Lock Relay
- Test anti-lock brake relay. Testing and Inspection
- Is anti-lock relay OK?
YES - Reinstall the relay and go to D4.
NO - Replace the anti-lock relay and Go to D6.

D4- Check Relay Control Circuit
- Disconnect connector C386 from anti-lock control module and connect breakout box and adapter.
- Measure the resistance between breakout box pin 4 and pin 1.
- Is resistance less than 150 ohms?
YES - Replace the anti-lock brake control module and go to D6.
NO - Repair circuit 908 (R/Y) and go to D6.

D5- Check Circuit
- Measure the voltage between breakout box pin 25 and ground.
- Is voltage greater than 10 volts?
YES - Repair short to B+ in circuit 907 (Y) and go to D6.
NO - Replace the anti-lock brake control module and go to D6.

D6- Verify Repair
- Restore vehicle. Reconnect all components.
- Clear all DTC's using the scan tool.
- Repeat the Drive Cycle Test.
- Retrieve DTC's using the scan tool.
- Is System Pass obtained?
YES - Stop. Repair is complete.
NO - If original code is retrieved, repeat Pinpoint Test D.
- If a different DTC is retrieved, return to DTC Index.