Circuit/System Verification
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.
P251A
- Ignition ON, verify that P0641 is not set as current in the PTO module.
- If the specified DTC is set as current, refer to DTC P0641 .
- Engine ON, press 1 on the PTO switch to engage PTO. The engine RPM should increase to the default engine speed within a few seconds. Press RES + to increase the engine speed and SET - to decrease the engine speed accordingly. Press 0 to disengage PTO and to return the engine speed back to normal idle.
P251E or P251F
- Engine ON, with PTO enabled using the in-cab PTO switch, momentarily press the 0 switch. The engine RPM should return to normal idle speed.
- With PTO enabled, momentarily press the remote engine shutdown switch. The engine RPM should return to normal idle speed and the engine will shutdown.