P0781: Automatic gearbox 1-2 shift malfunction
The automatic gearbox does not change cleanly from first to second: it is late, slips or never shifts. Fluid, solenoids or wear are likely.
| Code | P0781 |
|---|---|
| System | Engine and transmission |
| Group | P07xx, Transmission |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P0781 means
The transmission control unit commands the 1-2 shift and, comparing input and output shaft speeds, sees that the new gear did not engage properly. Because the fault is tied to this one shift, it helps narrow down which clutch or solenoid is involved.
Most common causes
- Low transmission fluid level or worn-out fluid
- Blocked transmission filter
- Solenoid controlling that shift sticking or poorly connected
- Gearbox speed sensor giving wrong readings
- Worn clutch or band for second gear
Symptoms
- The car holds first too long or will not go into second
- Clunk or slip during that shift
- Engine or gearbox warning light on
- Limp mode with limited gears
Can you drive with P0781?
With care You can drive gently, but pushing a slipping gearbox damages it quickly. Have it seen soon.
Open the bonnetthe in-depth explanation
How to check it
With live data, accelerate very lightly and watch the revs as it moves from first to second: if they flare up instead of dropping, the gear is slipping. Also check the fluid level and smell.
How to read and clear P0781 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 P0781 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
- P077D The gearbox output speed sensor circuit signal is too high
- P077E The gearbox oil temperature sensors give readings that do not agree
- P077F The gear ratio for reverse gear 2 is incorrect
- P0780 Automatic gearbox shift malfunction
- P0782 Automatic gearbox 2-3 shift malfunction
- P0783 Automatic gearbox 3-4 shift malfunction
- P0784 The shift from gear 4 to gear 5 has a fault
- P0785 The gearbox timing solenoid A is not working properly
- 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 P0781 mean?
The transmission control unit commands the 1-2 shift and, comparing input and output shaft speeds, sees that the new gear did not engage properly. Because the fault is tied to this one shift, it helps narrow down which clutch or solenoid is involved.
Can you drive with P0781?
You can drive gently, but pushing a slipping gearbox damages it quickly. Have it seen soon.
How do you clear P0781?
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, P0781 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.
