OBD-II · Engine and powertrain (P)
P0700
Transmission control system (MIL request)
What it means
The automatic transmission control unit has stored its own fault and asked the engine ECU to turn on the warning light. The real fault code is in the transmission unit.
Symptoms
- gearbox warning light or engine warning light
- harsh, delayed or no gear changes
- limp mode, stuck in one gear
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | any fault stored in the transmission control unit |
| 02 | low or degraded transmission fluid |
| 03 | sensor or solenoid fault in the gearbox or mechatronic unit |
| 04 | low battery voltage |
| 05 | wiring or communication fault |
What to check, step by step
- 01Read the fault codes in the transmission control unit with a scan tool that can access it
- 02Check the battery voltage and the transmission fluid level and condition
- 03Diagnose the specific transmission code(s) found