P03BC

Symptoms

• Check Engine light on
• Deteriorating fuel economy
• Engine vibration, especially at idle
• Reduced engine power
• Black or blue smoke from the exhaust pipe

Causes

• Worn or dirty spark plug for cylinder 4
• Faulty ignition coil
• Clogged fuel injector
• Reduced compression (wear of rings, valves)
• Violation of valve timing

How to Fix

1. Check the spark plug of cylinder 4 - visually and by measuring the gap
2. Move the ignition coil from another cylinder to check
3. Carry out a fuel system injector balance test
4. Perform a compression test on cylinder 4
5. Check valve timing using a data scanner
6. Replace faulty components and reset error codes

Related codes

Error P03BC by Vehicle Brand