Pinpoint Test R: The Hill Start Assist Indicator Is Never/Always On

Instrumentation, Message Center and Warning Chimes

Pinpoint Test R: The Hill Start Assist Indicator Is Never/Always On

Normal Operation

The Instrument Panel Cluster (IPC) receives the hill start assist indicator request from the ABS module over the High Speed Controller Area Network (HS-CAN) communication bus. When the hill start assist is active, the ABS module sends a request to the IPC (Instrument Panel Cluster) to illuminate the hill start assist indicator.

If the hill start assist request is missing or if the data is deemed invalid for less than 5 seconds, the hill start assist remains in the last indication mode (on or off) based on the last known good request received. If the hill start assist request is missing or if the data is deemed invalid by the IPC (Instrument Panel Cluster) for more than 5 seconds, the IPC (Instrument Panel Cluster) sets DTC U0121:00 in continuous memory and defaults the hill start assist indicator off.

NOTE: If DTC U0121:00 sets in the IPC (Instrument Panel Cluster), other observable symptoms may be brake, ABS or traction control warning indication concerns.

This pinpoint test is intended to diagnose the following:

- Hill start assist function concern

- ABS module

- IPC (Instrument Panel Cluster)

PINPOINT TEST R : THE HILL START ASSIST INDICATOR IS NEVER/ALWAYS ON

R1 CHECK THE OPERATION OF THE HILL START ASSIST FUNCTION

- Verify that the hill start assist function operates correctly. Refer to Hill Start Assist in Antilock Brakes / Traction Control Systems.

Does the hill start assist function operate correctly?

Yes
GO to R2.

No
GO to R4.

R2 CARRY OUT THE IPC (Instrument Panel Cluster) DEALER TEST MODE

- Ignition ON.

- Enter the IPC (Instrument Panel Cluster) dealer test mode. Scroll through the displays until LED is displayed.

Does the hill start assist indicator illuminate?

Yes
GO to R3
No
INSTALL a new IPC (Instrument Panel Cluster). REFER to Instrument Panel Cluster (IPC) Service and Repair. TEST the system for normal operation.

R3 RETRIEVE THE RECORDED DTCs FROM THE IPC (Instrument Panel Cluster) SELF-TEST

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

Is DTC U0121:00 recorded?

Yes
GO to Pinpoint Test AO Pinpoint Test AO: DTC U0121:00.

No
GO to R4.

R4 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
INSTALL a new ABS module. TEST the system for normal operation.