P0702 Code: Transmission Control System Electrical
⚠️ Severe · drivable
The transmission may go into limp mode or fail to shift. Drive only if it shifts safely, otherwise have it towed.
What P0702 means
The transmission control module (TCM) has an electrical fault, such as an internal failure or a problem with its power, ground, or wiring. This is more serious than a range code because the module itself may not be working properly.
Symptoms
- Check engine light is on
- Harsh shifts or no shifts
- Limp mode
- Transmission stuck in one gear
- Car won't move
Common causes
- most common: Faulty transmission control module
- common: Damaged wiring or connector to the TCM
- common: Poor power or ground to the TCM
- less common: Low battery voltage
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Check battery voltage and the charging system | Yes | $0–20 |
| Inspect and repair the TCM wiring and connectors | Mechanic | $100–400 |
| Replace the transmission control module | Mechanic | $400–1500 |
Frequently asked questions
Can I drive with a P0702 code?
It's risky. The transmission can go into limp mode or stop shifting. Drive only if it shifts safely, otherwise tow it.
What does the P0702 electrical code mean?
It means the transmission computer has an electrical fault — an internal failure, bad wiring, or a power and ground problem.
How much does it cost to fix a P0702?
Wiring repairs run $100–400; a new transmission control module is $400–1500 installed.
Related codes
P0700
P0700 Code: Transmission Control System Malfunction
P0701P0701 Code: Transmission Control System Range/Performance
P0705P0705 Code: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.