Powertrain, generic (extended)

P260C PTO Control Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P260C signals that the PTO control output reads too high, usually because the relay control line touches a powered wire or the relay coil draws too much current. GM lists it as P260C.00, a high voltage on the PTO relay control line, in the diagnostic table of the PTO module that GM fitted to Silverado and Sierra 3500 HD chassis cab trucks from 2008 to 2014. Since that module switches the relay on both its feed and its ground side, a short to voltage can leave the relay pulled in when it should have dropped out. Body builders splice into this circuit, so their added wiring is the likely suspect. CARB lets the OBD system pause selected monitors while a PTO runs, so a wrong PTO state matters beyond the work equipment. P260B is the low-side code, P260A the open circuit.

Likely causes

Relay control wire shorted to a powered circuit
Relay or solenoid coil with too low resistance
Faulty splice or add-on wiring from the body installation

Symptoms

  • PTO will not engage or will not release
  • PTO indicator behaves abnormally

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–400
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

pto engagement solenoidpto relaywiring harness

Related codes

P260AP260BP251C

References: gmupfitter.com, law.cornell.edu.