P085A: The gear shift control unit B communication has an electrical fault
The gear shift control unit B communication has an electrical fault. It may be the part itself, its connector or the wiring.
| Code | P085A |
|---|---|
| System | Engine and transmission |
| Group | P08xx, Transmission |
| Type | Generic: it means the same on every make |
How to read and clear P085A 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 P085A 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
- P0856 There is a fault in the traction control input signal
- P0857 The traction control input signal gives readings outside the normal range
- P0858 The traction control input signal gives a lower signal than normal
- P0859 The traction control input signal gives a higher signal than normal
- P085B The gear shift control unit B communication gives a lower signal than normal
- P085C The gear shift control unit B communication gives a higher signal than normal
- P085D The gear shift control unit A gives readings outside the normal range
- P085E The gear shift control unit B gives readings outside the normal range
- P0841 Transmission fluid pressure sensor/switch A: circuit range or performance
- P0842 Transmission fluid pressure sensor/switch A: circuit low
- P0843 Transmission fluid pressure sensor/switch A: circuit high
- P0868 Transmission fluid pressure low
What does code P085A mean?
The gear shift control unit B communication has an electrical fault. It may be the part itself, its connector or the wiring.
How do you clear P085A?
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, P085A 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.
