Pinpoint Test AC: The Tow Haul Message Center Indicator Is Never/Always On

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test AC: The Tow Haul Message Center Indicator Is Never/Always On

Normal Operation

The Instrument Cluster (IC) receives the tow haul status from the Transmission Control Module (TCM) over the High Speed Controller Area Network (HS-CAN) communication bus. The tow haul switch is hardwired to the TCM. When the tow haul feature is selected, the tow haul switch provides a ground signal to the TCM. The TCM upon receipt of the tow haul ground signal, provides a status message to the IC to illuminate the tow haul message center indicator. If the tow haul status message is missing or invalid for greater than 5 seconds, the IC sets DTC U0101 and defaults the tow haul message center indicator off.

This pinpoint test is intended to diagnose the following:

- TCM
- Message center concern

PINPOINT TEST AC: THE TOW HAUL MESSAGE CENTER INDICATOR IS NEVER/ALWAYS ON

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AC1 CHECK TRANSMISSION OPERATION


- Test drive the vehicle and turn the tow haul function on and off again.
- Does the tow haul function operate correctly?

Yes
GO to AC2.

No
REFER to Automatic Transaxle/Transmission External Controls Testing and Inspection.

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AC2 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST


- Check for recorded IC DTCs from the self-test.
- Is DTC U0101 recorded?

Yes
GO to Pinpoint Test AU. Pinpoint Test AU: DTC U0101

No
GO to AC3.

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AC3 RETRIEVE THE RECORDED DTCs FROM THE TCM SELF-TEST


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

Yes
REFER to Automatic Transaxle/Transmission - 6R80 Testing and Inspection.

No
GO to AC4.

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AC4 CHECK THE DOOR AJAR MESSAGE CENTER WARNING INDICATOR


- Close all doors, liftgate and liftgate glass.
- Ignition ON.
- Open the driver door while monitoring the door ajar message center warning indicator.
- Does the driver door ajar message center warning indicator turn off with the driver door closed and turn on with the driver door open?

Yes
INSTALL a new TCM. REFER to Automatic Transaxle/Transmission - 6R80 Mechatronic Assembly. TEST the system for normal operation.

No
GO to Pinpoint Test A. Pinpoint Test A: The Instrument Cluster (IC) Is Inoperative

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