Z DTC C1220

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

NORMAL OPERATION:
When the anti-lock brake control module receives ignition voltage, the anti-lock brake warning indicator in the instrument cluster is activated by the lamp driver in the anti-lock brake control module. The anti-lock brake warning indicator will illuminate for approximately 2 seconds. If all internal checks are OK, the lamp driver is de-energized and the anti-lock brake warning indicator is turned "OFF".

FAULT DESCRIPTION:
Diagnostic trouble code (DTC) C1220 (shorted anti-lock brake warning indicator) is generated when the anti-lock brake control module detects B+ to the anti-lock brake control module's anti-lock brake warning indicator input when the anti-lock brake warning indicator is supposed to be "ON".

POSSIBLE CONTRIBUTING CONDITIONS:
- Shorted anti-lock brake warning indicator miniature bulb.
- Defective lamp driver circuit in the anti-lock brake control module.
- Circuit 918 (Y/R) shorted to power between the anti-lock brake warning indicator and the anti-lock brake control module.

Z1- Check Anti-Lock Brake Warning Indicator Prove Out
- Clear all DTC's using the scan tool.
- Turn ignition switch to "RUN".

Anti-lock Brake Warning Indicator:

- Observe the anti-lock brake warning indicator.
- Lever the key in "RUN" for ten seconds.
- Does the anti-lock brake warning indicator come on for approximately 2 seconds and go out?
YES - Go to Z2.
NO - Go to Z3.

Z2- Verify ABS Control Module function
- Retrieve DTC's using the scan tool.
- Was DTC 1220 retrieved?
YES - Replace the anti-lock brake control module and go to Z5.
NO - Go to Z5.

Z3- Check For Short To Power
- Disconnect black 12 pin connector from instrument cluster.
- Disconnect connector C386 from anti-lock control module and connect breakout box and adapter.
- Measure the voltage between breakout box pin 17 and pin 1.
- is the voltage greater than 0 volts?
YES - Repair circuit 918 (Y/R) and go to Z6.
NO - Reconnect instrument cluster connector and go to Z4.

Z4- Isolate Fault
- Install a jumper wire between breakout box pin 17 and pin 1.
- Turn ignition switch to "RUN" and leave "ON" for ten seconds.
- Turn ignition switch to "OFF".
- Did the anti-lock brake warning indicator illuminate?
YES - The anti-lock brake warning indicator come "ON" brightly, replace the anti-lock brake control module and go to Z6.
NO - Check the anti-lock brake warning indicator.

Z5- Check Intermittent Wiring Concern
- Disconnect connector C386 from anti-lock control module and connect breakout box and adapter.
- Remove the 10A METER fuse(Wagons - 15A).
- Measure the voltage between breakout box pin 17 and pin 1.
- Wiggle the circuit starting at the end pints and move toward the middle while monitoring the voltage.
- Is any voltage detected?
YES - Repair circuit 918 (Y/R) go to Z6.
NO - Go to Z6.

Z6- 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 this Pinpoint Test.
- If a different DTC is retrieved, return to DTC Index.