Circuit/System Testing
WARNING: This page is about a different car, the 2021 GMC Sierra 3500 HD and 2021 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
This diagnostic procedure will only diagnose factory installed components. It will not diagnose upfitter provided equipment.
- Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the K44 Power Take - Off Control Module. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 1 V between the K44 Power Take - Off Control Module connector X2 terminal 8 and ground.
- If 1 V or greater
Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- If 1 V or greater
- Test for infinite resistance between the K44 Power Take - Off Control Module connector X2 terminal 8 and ground.
- If less than infinite resistance
Repair the short to ground on the circuit.
- Go to next step: If less than 2 Ω
- If less than infinite resistance
- Test for less than 2 Ω end to end between the K44 Power Take - Off Control Module connector X2 terminal 8 and the frame rail X176 Provisional Connector terminal G.
- If 2 Ω or greater
Repair the open/high resistance in the circuit.
- Go to next step: If less than 2 Ω
- If 2 Ω or greater
- Test or replace the K44 Power Take - Off Control Module.