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

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

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

Normal Operation

The status of the ABS system is sent to the Instrument Cluster (IC) from the ABS module over the High Speed Controller Area Network (HS-CAN) communication bus. The IC monitors the ABS input and illuminates the ABS warning indicator when a concern is present.

If the ABS message is missing for less than 5 seconds, the ABS warning indicator remains in the last indication mode (on or off). If the ABS message is missing for more than 5 seconds, the IC sets DTC U0121 in continuous memory and defaults the ABS and brake warning indicators on.

NOTE: If the brake system experiences an Electronic Brake Distribution (EBD) failure, both the brake warning indicator and the ABS warning indicators illuminate.

This pinpoint test is intended to diagnose the following:

- ABS module
- IC



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

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O1 CARRY OUT THE IC INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC ABS warning indicator (ABS_LAMP) active command and command the ABS warning indicator on and off. Observe the ABS warning indicator.
- Does the ABS warning indicator illuminate when commanded on and turn off when commanded off?

Yes
GO to O2.

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

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O2 RETRIEVE THE RECORDED DTCs FROM THE ABS MODULE SELF-TEST


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

Yes
REFER to Antilock Brakes / Traction Control Systems.

No
GO to O3.

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O3 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST


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

Yes
For DTC U0121, GO to Pinpoint Test AW. Pinpoint Tests AW: DTC U0121

For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes

No
If the ABS warning indicator is never on, the system is operating correctly at this time.

If the ABS warning indicator is always on, INSTALL a new ABS module. REFER to Antilock Brakes / Traction Control Systems. TEST the system for normal operation.

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