PTO Enable Switch Circuit/Open
The Power Take-Off (PTO) enable switch input to the ECM is open. PTO is used on trucks and work vehicles to drive auxiliary equipment from the engine — without a valid enable signal the ECM refuses to enter PTO operating mode, idle speed control changes do not apply.
Affected components
- Pto enable switch
- Wiring harness
Common causes
- High likelihood: Open switch wire or unplugged switch
- Medium likelihood: Failed PTO enable switch
- Low likelihood: Pin pushed back out of connector body
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.