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

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

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

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 message center indicator.

If the grade assist on/off message is missing for less than 5 seconds, the grade assist message center indicator remains in the last indication mode (on or off) based upon the last good known 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 message center 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:

- Grade assist system concern
- Transaxle concern
- PCM
- IPC



PINPOINT TEST W: THE GRADE ASSIST MESSAGE CENTER 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 when engaged and turns off when disengaged.
- Does the grade assist function operate correctly?

Yes
GO to W2.

No
REFER to Automatic Transmission/Transaxle.

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W2 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 W3.

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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W3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST


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

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

No
GO to W4.

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W4 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. REFER to Computers and Control Systems. TEST the system for normal operation.

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