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

External Controls - Column Shift


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.

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 Instrument Panel, Gauges and Warning Indicators if the Tow/Haul lamp does not illuminate.

C2 CHECK THE BCM (Body Control Module) FUSE 42 (5A)

- Ignition OFF.

- Remove Body Control Module (BCM) fuse 42 (5A).

- Check fuse: BCM (Body Control Module) 42 (5A).

Is the resistance less than 5 ohms?

Yes
GO to C4.
No
GO to C3.

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

- Disconnect: Tow/Haul C2399.

- Disconnect: BCM (Body Control Module) 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 (Key ON Engine Running) self-test and test the system for normal operation.

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 C5.
No
REPAIR circuit CBP42 (GN) for an open. CLEAR the DTC. RERUN the KOER (Key ON Engine Running) self-test and test the system for normal operation.

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 (Body Control Module) 42 (5A). CLEAR the DTC. RERUN the KOER (Key ON Engine Running) self-test and test the system for normal operation.

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 . CLEAR the DTC. RERUN the KOER (Key ON Engine Running) 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 Transmission/Transaxle &/or Transmission Control Systems Solenoid Body Strategy. RERUN the KOER (Key ON Engine Running) self-test and test the system for normal operation.