Pinpoint Test J : The Abs (Anti-Lock Brake System) Warning Indicator Is Never Or Always On
- Normal Operation and Fault Conditions
If the ABS warning indicator status message is missing for less than the defined time threshold, the IPC defaults the ABS warning indicator to its last state (on or off), based upon the last message received.
If the BCM does not receive the ABS warning indicator request message from the ABS module, the BCM sets DTC U0121:00.
If the IPC does not receive the ABS warning indicator request message from the BCM for longer than the programmed time threshold, the BCM sets DTC U0121:00 and defaults the ABS warning indicator on.
See ABS Warning Indicator. REFER to: Instrument Panel Cluster (IPC) - System Operation and Component Description .
Possible Sources
- ABS concern
- BCM concern
- IPC
- J1 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE IPC (INSTRUMENT PANEL CLUSTER) SELF-TEST
- Ignition ON.
- Using a diagnostic scan tool, perform the IPC self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes REFER to DTC Chart: IPC . No GO to J2 - J2 CARRY OUT THE IPC (INSTRUMENT PANEL CLUSTER) INDICATOR LAMP CONTROL ACTIVE COMMAND USING A DIAGNOSTIC SCAN TOOL
- Using a diagnostic scan tool, view the IPC Parameter Identifications (PIDs).
- Select the IPC ABS warning indicator (ABS_LAMP) PID.
- Command the ABS warning indicator on then off. Observe the ABS warning indicator.
Does the ABS warning indicator turn on when commanded on and turn off when commanded off?
Yes GO to J3 No Refer to IPC Guided Routine Testing . - J3 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE BCM (BODY CONTROL MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the BCM self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes REFER to: Body Control Module (BCM) . No If the ABS warning indicator is always on, DIAGNOSE the ABS. REFER to: Anti-Lock Brake System (ABS) And Stability Control . If the ABS warning indicator is never on, the system is operating correctly.