P0702: Transmission control system: electrical fault
The ECU detects an electrical problem in the automatic gearbox system: power supply, earth, wiring or connectors at the gearbox.
| Code | P0702 |
|---|---|
| System | Engine and transmission |
| Group | P07xx, Transmission |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P0702 means
On cars with an automatic gearbox, the transmission control unit monitors its own sensors and solenoids. This code points to an electrical fault in that system without naming the part: it may be the power supply or earth to the transmission control unit, or the wiring to the sensors and solenoids.
Most common causes
- Low battery or loose terminals
- Blown transmission control unit fuse
- Loose or corroded gearbox or control unit earth
- Gearbox connector with oil seeping inside
- Damaged wiring between the control unit and the gearbox
- 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 P0702?
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
Check the battery, terminals and gearbox fuses, and see whether the gearbox connector shows traces of oil. 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 P0702 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 P0702 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
- P0700 Transmission control system: fault detected
- P0701 Transmission control system: range/performance
- 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
- P0712 Transmission fluid temperature sensor: circuit low
- P0713 Transmission fluid temperature sensor: circuit high
What does code P0702 mean?
On cars with an automatic gearbox, the transmission control unit monitors its own sensors and solenoids. This code points to an electrical fault in that system without naming the part: it may be the power supply or earth to the transmission control unit, or the wiring to the sensors and solenoids.
Can you drive with P0702?
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 P0702?
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, P0702 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.
