Pinpoint Test Q: The ABS Warning Indicator Is Never/Always On

Instrumentation, Message Center and Warning Chimes

Pinpoint Test Q: The ABS Warning Indicator Is Never/Always On

Normal Operation

The ABS module provides the ABS warning indicator request to the Instrument Panel Cluster (IPC) over the High Speed Controller Area Network (HS-CAN) communication bus. If a fault condition exists in the ABS, the ABS module sends the IPC (Instrument Panel Cluster) a request to turn on the ABS warning indicator. If the ABS warning indicator request message is missing for less than 5 seconds, the ABS warning indicator remains in the last indication state (on or off) based upon the last known good message received.

If the ABS warning indicator status message is missing for less than 5 seconds, the IPC (Instrument Panel Cluster) defaults the ABS warning indicator to its last state (on or off) based upon the last known good message received. If the ABS warning indicator request message is missing for more than 5 seconds, the IPC (Instrument Panel Cluster) sets DTC U0121:00 and defaults the ABS warning indicator on.

This pinpoint test is intended to diagnose the following:

- ABS module

- IPC (Instrument Panel Cluster)

PINPOINT TEST Q : THE ABS WARNING INDICATOR IS NEVER/ALWAYS ON

Q1 CARRY OUT THE IPC (Instrument Panel Cluster) INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: IPC (Instrument Panel Cluster) DataLogger.

- Select the IPC (Instrument Panel Cluster) ABS warning indicator (ABS_LAMP) active command. Command the ABS warning indicator on then off. Observe the ABS warning indicator.

Does the ABS warning indicator turn off when commanded off?

Yes
GO to Q2.

No
INSTALL a new IPC (Instrument Panel Cluster). REFER to Instrument Panel Cluster (IPC) . TEST the system for normal operation.

Q2 RETRIEVE THE RECORDED DTCs FROM THE IPC (Instrument Panel Cluster) SELF-TEST

- Check for recorded IPC (Instrument Panel Cluster) DTCs from the self-test.

Are any DTCs recorded?

Yes
For DTC U0121:00, GO to Pinpoint Test BD. Pinpoint Test BD: DTC U0121:00

For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes
No
GO to Q3.

Q3 RETRIEVE THE RECORDED DTCs FROM THE ABS MODULE SELF-TEST

- Check for recorded ABS module DTCs from the self-test.

Are any DTCs recorded?

Yes
REFER to Antilock Brakes / Traction Control Systems.

No
If the ABS warning indicator is always on, INSTALL a new ABS module. TEST the system for normal operation.

If the ABS warning indicator is never on, the system is operating correctly at this time.