The computer sees a fault in the circuit of coil A, usually the coil for cylinder 1. The driver may notice a misfire, shaking and weak power.
Causes vary by car. Test before you order a part.
Likely causes, most common first
- Faulty ignition coil
- Damaged wiring or connector
- Poor coil ground
- Worn spark plug stressing the coil
Parts usually involved
- Ignition coil Find at suppliers
- Spark plug Find at suppliers
- Coil connector Find at suppliers
Test before you replace
Swap the coil with another cylinder and check power and control signal at the connector.
General guidance for generic OBD2 codes. Always follow the maker's procedure for the car in front of you.