WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
DTC P253D
Circuit
Short to Ground
Open/High Resistance
Short to Voltage
Signal Performance
PTO Engage Signal
1
1
P253D 00
1
1. Power Take-Off (PTO) Does Not Increase With Power Take-Off Engaged