Ignition Coils
Ignition Coils
Section titled “Ignition Coils”The M54 uses 6 individual coil-on-plug ignition coils. They are a common failure point as the car ages.
Symptoms
Section titled “Symptoms”- Misfires (P0301-P0306)
- Rough idle
- Check engine light (flashing = active misfire)
- Reduced power
Diagnosis
Section titled “Diagnosis”Swap suspected coil to a different cylinder. If the misfire follows the coil, replace it.
Replacement
Section titled “Replacement”Replace all 6 at the same time — they’re the same age. Bosch or Delphi recommended. See DIY: Spark Plug Replacement for procedure (coils are removed in the same process).