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

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

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 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 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 sets DTC U0121:00 and defaults the ABS warning indicator on.

This pinpoint test is intended to diagnose the following:

- ABS module
- IPC

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

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Q1 CARRY OUT THE IPC INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC DataLogger.
- Select the IPC 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. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.

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Q2 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST

- Check for recorded IPC DTCs from the self-test.
- Are any DTCs recorded?

Yes
For DTC U0121:00, GO to Pinpoint Test BD. For all other DTCs, REFER to DTC Charts. Pinpoint Tests BD: DTC U0121:00

No
GO to Q3.

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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 Vehicle Dynamic Systems Testing and Inspection.

No
If the ABS warning indicator is always on, INSTALL a new ABS module. REFER to Vehicle Dynamic Systems Service and Repair. TEST the system for normal operation. If the ABS warning indicator is never on, the system is operating correctly at this time.

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