P0700: Transmission control system: fault detected
The automatic gearbox control unit has found a fault and asked for the warning light; the details are in the gearbox’s own codes.
| Code | P0700 |
|---|---|
| System | Engine and transmission |
| Group | P07xx, Transmission |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P0700 means
On cars with an automatic gearbox, the transmission control unit monitors its own sensors and solenoids. When it finds a problem it stores its own code and asks the engine ECU to switch on the warning light. This code is that request: it does not say what has failed, only that the gearbox has a fault stored.
Most common causes
- Low or badly degraded gearbox oil
- Loose or corroded connector at the transmission control unit or gearbox
- Faulty gearbox sensor or solenoid (its own code will say which)
- Damaged gearbox wiring
- Low battery causing voltage dropouts
- Transmission control unit fault
Symptoms
- Engine or gearbox warning light on
- Harsh, late or missed gear changes
- Gearbox stuck in one gear (limp mode)
- Car feels sluggish when accelerating
Can you drive with P0700?
With care You can drive with care, but the gearbox may lock into one gear and an ignored fault can cause further damage. Have it checked soon.
Open the bonnetthe in-depth explanation
How to check it
This code is only a flag. The specific fault is stored in the transmission control unit: have it read, or use a scanner that can reach it, before replacing any parts.
How to read and clear P0700 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 P0700 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
- P0701 Transmission control system: range/performance
- P0702 Transmission control system: electrical fault
- P0703 Torque converter/brake switch B: circuit fault
- P0704 Fault in the clutch pedal switch
- P0705 Transmission range sensor: circuit fault
- P0706 Transmission range sensor: range/performance
- P0710 Transmission fluid temperature sensor: circuit fault
- P0711 Transmission fluid temperature sensor: range/performance
To understand it properly
We explain how that system works, with drawings and no waffle, in our mechanics guide: Automatic gearbox.
What does code P0700 mean?
On cars with an automatic gearbox, the transmission control unit monitors its own sensors and solenoids. When it finds a problem it stores its own code and asks the engine ECU to switch on the warning light. This code is that request: it does not say what has failed, only that the gearbox has a fault stored.
Can you drive with P0700?
You can drive with care, but the gearbox may lock into one gear and an ignored fault can cause further damage. Have it checked soon.
How do you clear P0700?
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, P0700 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.
