Power Take-Off Unit
Drives something other than the wheels from the engine or gearbox — a tipper ram, a mixer drum, a crane, a compressor, a vacuum pump, a winch, a sweeper's brushes. Its control module does not run the equipment; it publishes whether the PTO is engaged, and a set of interlocks is decided from that one value.
Those interlocks are why a PTO fault is a safety matter rather than an inconvenience. Engagement is normally permitted only with the vehicle stationary, the correct gear or neutral selected, the parking brake applied and often a door closed; once engaged, the engine's idle and maximum speeds change, road speed is limited or drive inhibited, and the transmission may be locked out.
So an implausible state can let equipment run when it should not, refuse to release drive to the road, or govern the engine for no visible reason — the last of which reads as a fuelling fault.
PTO wiring is almost always installed by the body builder rather than the vehicle manufacturer, so the join between chassis and body wiring is where these faults live, and the converter is often better placed to find them than a franchised workshop.
Also known as: pto, power take off, power takeoff, pto unit, pto drive, auxiliary drive
Referenced by 42 codes
Codes involving this component (42)
- U0117 Lost Communication With PTO Control Module High
- U0465 Invalid Data Received From PTO Control Module High
- P064B PTO Control Module Moderate
- P253D PTO Sense Circuit High Moderate
- U0080 Vehicle Communication Bus F Moderate
- U0081 Vehicle Communication Bus F Performance Moderate
- U0082 Vehicle Communication Bus F (+) Open Moderate
- U0083 Vehicle Communication Bus F (+) Low Moderate
- U0084 Vehicle Communication Bus F (+) High Moderate
- U0085 Vehicle Communication Bus F (-) Open Moderate
- U0086 Vehicle Communication Bus F (-) Low Moderate
- U0087 Vehicle Communication Bus F (-) High Moderate
- U0088 Vehicle Communication Bus F (-) Shorted to Bus F (+) Moderate
- P251A PTO Enable Switch Circuit/Open
- P251B PTO Enable Switch Circuit Low
- P251C PTO Enable Switch Circuit High
- P251D PTO Engine Shutdown Circuit/Open
- P251E PTO Engine Shutdown Circuit Low
- P251F PTO Engine Shutdown Circuit High
- P253A PTO Sense Circuit/Open
- P253B PTO Sense Circuit Range/Performance
- P253C PTO Sense Circuit Low
- P253E PTO Sense Circuit Intermittent/Erratic
- P254A PTO Speed Selector Sensor/Switch 1 Circuit/Open
- P254B PTO Speed Selector Sensor/Switch 1 Range/Performance
Other components in Transmission
- Transmission Control Module 485
- Valve Body 334
- Transmission Fluid 308
- Pressure Control Solenoid 181
- Shift Solenoid 167
- Clutch Pack 122
- Clutch Actuator 89
- Shift Fork 72
- Gear Shift Actuator 72
- Transmission Fluid Pressure Sensor 70
- Electric/Auxiliary Transmission Fluid Pump 67
- Gear Lever Position Sensor 65
- Transmission Range Sensor 58
- Gear Shift Module 58
- Park/Neutral Switch 40
- Transmission Fluid Temperature Sensor 33
- Clutch Position Sensor 29
- Torque Converter 28
- Transmission Mode Switch 24
- Engine Disconnect Clutch 22
- Transmission Fluid Pump 22
- Transmission Fluid Filter 19
- Torque Converter Clutch Solenoid 17
- Output Speed Sensor 16
- Clutch 15
- Four Wheel Drive Switch 14
- Hydraulic Power Unit 14
- Four-Wheel Drive Clutch Control Module 14
- Manual Shift Switch 13
- Gate Select Actuator 13
- Transfer Case 11
- Intermediate Shaft Speed Sensor 10
- Shift Lock Solenoid 10
- Transfer Case Control Module 10
- Hydraulic Pressure Sensor 8
- Turbine Speed Sensor 7
- Skip Shift Solenoid 5
- Hydraulic Oil Temperature Sensor 5
- Transmission Fluid Cooler 4
- Reverse Inhibit Solenoid 4
- Driveline Disconnect Switch 4
- Reverse Light Switch 2
- Synchroniser 2
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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