Pinpoint Test W: The Grade Assist Indicator Is Never/Always On

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test W: The Grade Assist Indicator is Never/Always On

Normal Operation

The Instrument Panel Cluster (IPC) receives the grade assist status from the Transmission Control Module (TCM) (part of the PCM) over the High Speed Controller Area Network (HS-CAN) communication bus. When the grade assist function is selected on, the TCM sends a message to the IPC to illuminate the grade assist indicator.

If the grade assist message is missing for less than 5 seconds, the grade assist indicator remains in the last on/off state, based upon the last known good grade assist message received.

If the grade assist off message is missing for more than 5 seconds, DTC U0100:87 sets in continuous memory and defaults the grade assist indicator off.

This pinpoint test is intended to diagnose the following:

- Transmission concern
- PCM
- IPC

PINPOINT TEST W: THE GRADE ASSIST INDICATOR IS NEVER/ALWAYS ON

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W1 CHECK THE OPERATION OF THE GRADE ASSIST FUNCTION


- Verify that the grade assist function operates correctly.
- Does the grade assist function correctly?

Yes
GO to W2.

No
REFER to Automatic Transaxle/Transmission - 6R80 Testing and Inspection.

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W2 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 grade assist (OVERDRV) active command on and off while monitoring the grade assist indicator.
- Monitor the grade assist indicator.
- Does the grade assist indicator illuminate when commanded on, and turn off when commanded off?

Yes
GO to W3.

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

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W3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST


- Check for recorded DTCs from the IPC self-test.
- Is DTC U0100:87 recorded?

Yes
GO to Pinpoint Test AQ. Pinpoint Test AQ: DTC U0100:87

No
GO to W4.

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W4 RETRIEVE THE RECORDED TCM DTCs FROM THE SELF-TEST


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

Yes
REFER to the Diagnostic Trouble Code (DTC) Chart in Multifunction Electronic Modules Multifunction Electronic Modules.

No
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. TEST the system for normal operation.

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