Fault code P0350 – a step-by-step guide to diagnosing and fixing it

Error code P0350 is displayed and the check engine light is on - what does this mean?

The OBD/EOBD system has detected an error in the ignition coil primary circuit. This DTC P0350 indicates a problem with the ignition coil primary circuit, which is responsible for the proper ignition of the fuel-air mixture. The trouble code can occur with various manufacturers and affects the entire ignition system.

What causes can this fault code have?

• Defective ignition coil
• Damaged cable connections to the ignition coil
• Loose or corroded plug connections
• Defective ignition control unit (PCM/ECM)
• Interrupted power supply to the ignition coil
• Short circuit in the primary circuit
• Defective fuse in the ignition circuit
• Faulty earth lead

What symptoms occur in parallel with fault code P0350?

• Starting problems: The vehicle is difficult to start or does not start at all
• Engine misfires: Irregular engine running and jerky driving
• Loss of power: Reduced engine power, especially when accelerating
• Increased fuel consumption: Poor combustion leads to higher fuel consumption
• Black smoke: Incomplete combustion causes dark exhaust emissions
• Knocking noises: Metallic noises from the engine compartment

How to fix the problem of error code P0350?

• The repair requires a systematic diagnosis of the ignition system to identify the exact cause.
• Replace the ignition coil and check the electrical connections, as defective coils are the most common cause
• Check all cable connections to the ignition coil for damage, corrosion or loose contacts and repair if necessary
• Check fuses in the ignition circuit and replace defective fuses
• Diagnose the ignition control unit (PCM/ECM) and have it replaced if defective
• Check the ignition coil earth lead and ensure that it is properly earthed
• Measure the entire wiring of the ignition system with a multimeter and repair damaged areas