P078F: The circuit of gearbox mode selection switch C has a fault
The circuit of gearbox mode selection switch C has a fault.
| Code | P078F |
|---|---|
| System | Engine and transmission |
| Group | P07xx, Transmission |
| Type | Generic: it means the same on every make |
How to read and clear P078F 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 P078F 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
- P078B The gearbox timing solenoid B gives readings outside the normal range
- P078C The gearbox timing solenoid B gives a lower signal than normal
- P078D The gearbox timing solenoid B gives a higher signal than normal
- P078E The gearbox timing solenoid B fails now and then
- P0790 There is a fault in the normal mode switch circuit
- P0791 The intermediate shaft speed sensor has an electrical fault
- P0792 The intermediate shaft speed sensor gives readings outside the normal range
- P0793 The intermediate shaft speed sensor sends no signal
- 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 P078F mean?
The circuit of gearbox mode selection switch C has a fault.
How do you clear P078F?
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, P078F 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.
