Pinpoint Tests AI: The Grade Assist Indicator Is Never/Always On (Without Select Shift)

Instrumentation, Message Center and Warning Chimes

Pinpoint Test AI: The Grade Assist Indicator Is Never/Always On (Without Select Shift)

Normal Operation

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

If the grade assist on/off message is missing for less than 5 seconds, the grade assist indicator remains in the last state (on or off) based upon the last known good message. If the grade assist on/off message is missing for more than 5 seconds, the IPC sets DTC U0100:00 in continuous memory and defaults the grade assist indicator off.

NOTE: If DTC U0100:00 is set in the IPC, other observable symptoms may be an inoperative speedometer, tachometer or odometer.

This pinpoint test is intended to diagnose the following:

- Transaxle concern
- PCM
- Instrument Panel Cluster (IPC)


PINPOINT TEST AI: THE GRADE ASSIST INDICATOR IS NEVER/ALWAYS ON (WITHOUT SELECT SHIFT)

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AI1 CHECK THE OPERATION OF THE GRADE ASSIST FUNCTION

- Verify that the grade assist function operates when engaged and turns off when disengaged.
- Does the grade assist function operate correctly?

Yes
GO to AI2.

No
REFER to Automatic Transaxle/Transmission External Controls - Aisin AW21/6F35 Testing and Inspection.

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AI2 CARRY OUT THE IPC GRADE ASSIST INDICATOR ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC DataLogger .
- Select the IPC grade assist indicator (TRAILER_LMP) active command. Command the grade assist indicator on and off while observing the grade assist indicator.
- Does the grade assist indicator illuminate when commanded on, and turn off when commanded off?

Yes
GO to AI3.

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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AI3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST

- Check for recorded IPC DTCs from the self-test.
- Is DTC U0100:00 recorded?

Yes
GO to Pinpoint Test BF. Pinpoint Tests BF: DTC U0100:00

No
GO to AI4.

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AI4 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO SELF-TEST

- Check for recorded PCM DTCs from the Key ON Engine OFF (KOEO) self-test.
- Are any DTCs recorded?

Yes
REFER to Computers and Control Systems Information.

No
INSTALL a new PCM. TEST the system for normal operation.

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