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

C1 CHECK CIRCUIT CET34 (BN/GN) FOR VOLTAGE

- Disconnect: Tow/Haul Switch C2399.

- Inspect C2399 for damaged or pushed-out terminals, corrosion or loose wires. Repair as necessary.

- Ignition ON.

- Measure the voltage between the tow/haul switch, C2399-2, circuit CET34 (BN/GN), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to C3.

No
GO to C2.

C2 CHECK CIRCUIT CET34 (BN/GN) FOR AN OPEN

- Disconnect: Transmission Vehicle Harness C1548.

- Inspect C1548 for damaged or pushed-out terminals, corrosion or loose wires. Repair as necessary.

- Measure the resistance between the tow/haul switch, C2399-2, circuit CET34 (BN/GN) and the transmission vehicle harness, C1548-1, circuit CET34 (BN/GN), harness side.





Is the resistance less than 5 ohms?

Yes
GO to C3.

No
REPAIR circuit CET34 (BN/GN) for an open. TEST the system for normal operation.

C3 CHECK CIRCUIT GD133 (BK) FOR AN OPEN

- Measure the voltage between the tow/haul switch, C2399-2 and C2399-1, harness side.





Is the voltage greater than 10 volts?

Yes
INSTALL a new selector lever. REFER to Selector Lever - Column Shift . TEST the system for normal operation.

No
REPAIR circuit GD133 (BK) for an open. If no open is found, REPLACE the Transmission Control Module (TCM). TEST the system for normal operation.