P260B is stored when the PTO control output reads too low, the classic case being a grounded wire leading to the PTO relay coil. GM documents the code as P260B.00, a low voltage on the PTO relay control line, among the faults the PTO module can set on 2008-2014 Silverado and Sierra 3500 HD chassis cabs. That module drives both ends of an upfitter-supplied relay, energizes it when the in-cab switch requests PTO and drops it again once engine speed is back at base idle; a ground fault on its control side therefore prevents engagement. Because the relay and its wiring are added by the body builder, their routing and protection deserve the first look. P260A is the open circuit, P260C the high-side fault. The truck still drives, only the PTO stays off.
Medium severity. Can I keep driving?If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
Symptoms
- PTO cannot be engaged
- Message or flashing PTO indicator
Most likely causes
- Relay control wire chafed against the frame or body
- Shorted coil in the PTO relay or solenoid
- Relay wired incorrectly during body installation
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
What each character of P260B means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 6: Control modules and outputs
- 0B: Specific fault in that system
Frequently asked questions
Can I keep driving with code P260B?
If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
What causes code P260B?
The most common causes are: relay control wire chafed against the frame or body; shorted coil in the PTO relay or solenoid; relay wired incorrectly during body installation.
Related codes
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.