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Pinpoint Test C: The Tow/Haul Switch Does Not Operate Correctly




External Controls - Column Shift

Pinpoint Tests

PINPOINT TEST C: THE TOW/HAUL SWITCH DOES NOT OPERATE CORRECTLY

NOTE: Vehicles equipped with a 3.7L engine use PCM C175T.

NOTE: Vehicles equipped with a 5.0L or 6.2L engine use PCM C1381T.

NOTE: Vehicles equipped with a 3.5L engine use PCM C1551B.

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C1 CHECK DTCs

- Ignition ON.
- Connect the scan tool.
- Start the engine and RUN the Key ON Engine Running (KOER) self-test.
- Is DTC P1780 set?

Yes
GO to C2.

No
No trouble found with the Tow/Haul system. REFER to Instrumentation, Message Center, and Warning Chimes Testing and Inspection if the Tow/Haul lamp does not illuminate.

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C2 CHECK THE BCM FUSE 42 (5A)

- Ignition OFF.
- Remove Body Control Module (BCM) fuse 42 (5A).
- Check fuse: BCM 42 (5A).
- Is the resistance less than 5 ohms?

Yes
GO to C4.

No
GO to C3.

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C3 CHECK THE TOW/HAUL POWER CIRCUIT FOR A SHORT TO GROUND

- Disconnect: Tow/Haul C2399.
- Disconnect: BCM C2280B.
- Inspect C2399 and C2280B for damaged, pushed-out terminals or loose wires.
- Measure the resistance between the Tow/Haul C2399-1, circuit CBP42 (GN), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to C4.

No
REPAIR circuit CBP42 (GN) for a short to ground. CLEAR the DTC. RERUN the KOER self-test and test the system for normal operation.

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C4 CHECK THE TOW/HAUL POWER CIRCUIT FOR VOLTAGE

- Disconnect: Tow/Haul C2399.
- Inspect C2399 for damaged, pushed-out terminals or loose wires.
- Ignition ON.
- Measure the voltage between the Tow/Haul switch C2399-1, circuit CBP42 (GN), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to C6.

No
REPAIR circuit CBP42 (GN) for an open. CLEAR the DTC. RERUN the KOER self-test and test the system for normal operation.

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C5 CHECK THE TOW/HAUL INPUT CIRCUIT FOR A SHORT TO GROUND

- Disconnect: PCM C175T.
- Disconnect: PCM C1381T.
- Disconnect: PCM C1551B.
- Inspect the connector for damaged, pushed-out terminals, corrosion or loose wires.
- Measure the resistance between Tow/Haul switch C2399-2, circuit CET34 (BN/GN) and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to C6.

No
REPAIR circuit CET34 (BN/GN) for a short to ground. REPLACE the BCM 42 (5A). CLEAR the DTC. RERUN the KOER self-test and test the system for normal operation.

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C6 CHECK THE TOW/HAUL INPUT CIRCUIT FOR AN OPEN

- Connect the scan tool.
- Enter the following diagnostic mode on the scan tool: TCS_DEPRES.
- Connect a fused jumper from Tow/Haul switch, C2399-1 to C2399-2, harness side.




- Does the TCS_DEPRES PID display YES?

Yes
REPLACE the selector lever. REFER to Selector Lever - Column Shift Selector Lever - Column Shift. CLEAR the DTC. RERUN the KOER self-test and test the system for normal operation.

No
INSPECT and REPAIR circuit CET34 (BN/GN) for an open. If an open circuit is not found, REPLACE the PCM. PERFORM the Solenoid Body Strategy Data Download procedure. REFER to Automatic Transaxle/Transmission - 6R80 Solenoid Body Strategy. RERUN the KOER self-test and test the system for normal operation.

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