Circuit/System Testing
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the in-cab PTO switch.
- Ignition ON, test for 4.5 to 5.2 volts on the vehicle harness connector between the following terminals:
- 2 and ground
- 9 and ground
- 4 and ground
- 1 and ground
- If less than the specified range, disconnect the harness connector at the PTO module and test the failed signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PTO switch.
- If greater than the specified range, test the failed signal circuit for a short to voltage. If the circuit tests normal, test or replace the PTO module.
- Ignition OFF, test for less than 0.5 ohm of resistance between the ground circuit terminal 5 and ground.
- If greater than the specified value, test the ground circuit terminal 5 for a high resistance. If the circuit tests normal, replace the PTO module.
- If the circuits test normal, replace the PTO switch.