Engine and gearbox (P)
P0606: ECM/PCM processor fault
The engine control module (ECM) or powertrain control module (PCM) has detected an internal processor fault. This may affect the vehicle's ability to manage engine functions properly.
Checked by a licensed car technician · last reviewed 29 September 2026
Symptoms
- Engine warning light on
- Poor engine performance
- Possible stalling
- Reduced fuel efficiency
Common causes
- Low voltage event
- Water ingress
- Module failure
How to check it yourself
- Check battery voltage and connections
- Inspect for signs of water damage
- Read all stored codes
- Check module grounds and power supply
- Consider professional diagnosis if unresolved
Can I keep driving?
If the engine warning light is flashing or the car is stalling, do not drive the vehicle.
General guidance, not a professional inspection. Confirm faults with measurements before buying parts, and use a qualified mechanic for brakes, steering, fuel leaks, airbags, and other safety-critical work. Terms and disclaimer