FixVault

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.
  1. Ignition OFF, disconnect the PTO relay.
  2. Igniton ON, test for 11 volts or greater between the PTO relay supply voltage circuit terminal 86 and ground.
    • If less than the specified voltage, test the PTO relay supply voltage circuit for a short to ground or an open/high resistance.
  3. Ignition OFF, disconnect the harness connector at the PTO module.
  4. Ignition ON, test for 0 volts between the PTO relay coil control circuit terminal 28 and ground.
    • If greater than the specified value, test the PTO relay control circuit for a short to voltage.
  5. Ignition OFF, connect the PTO relay.
  6. Ignition ON, test for 11 volts or greater between the PTO relay coil control circuit terminal 28 and ground.
    • If less than the specified voltage, test the PTO relay coil control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the PTO relay.
  7. If all circuits test normal, replace the PTO module.