P0739: The gearbox control unit engine speed output signal is too high
The gearbox control unit engine speed output signal is too high. Check the unit, its connector and wiring.
| Code | P0739 |
|---|---|
| System | Engine and transmission |
| Group | P07xx, Transmission |
| Type | Generic: it means the same on every make |
How to read and clear P0739 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0739 with its description and whether it’s confirmed, pending or permanent.
This code is usually stored by the gearbox control unit. If the car reports it over standard OBD, you read it for nothing with FREE; to read it straight from the gearbox control unit, with its description and clearing, you need PRO.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P0735 Incorrect gear ratio in fifth gear
- P0736 The gearbox is not getting the correct ratio in reverse
- P0737 The gearbox control unit motor speed output has an electrical fault
- P0738 The gearbox control unit motor speed output gives a lower signal than normal
- P073A The gearbox is stuck in gear 5
- P073B The gearbox is stuck in gear 6
- P073C The gearbox is stuck in gear 7
- P073D The gearbox cannot select neutral gear
- P0700 Transmission control system: fault detected
- P0701 Transmission control system: range/performance
- P0702 Transmission control system: electrical fault
- P0703 Torque converter/brake switch B: circuit fault
What does code P0739 mean?
The gearbox control unit engine speed output signal is too high. Check the unit, its connector and wiring.
How do you clear P0739?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P0739 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
