3.2L I6 S54โ€ขRWDโ€ขAUTOMATICโ€ขgasโ€ขS54B32
5 active safety recalls on this vehicle โ€” view recalls
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B0420moderate severityBody

Check Engine Lamp Circuit

on 2002 BMW M3 3.2L I6 S54 ยท RWD

What this code means

Malfunction in the check engine/MIL indicator lamp circuit in the instrument cluster.

Symptoms

  • Check engine light does not illuminate during bulb check
  • Light stays on with no DTC stored
  • Light flickering
  • Cannot determine if engine codes are present

Common causes

  • Burnt out MIL bulb/LED
  • Cluster circuit board fault
  • Wiring from PCM to cluster damaged
  • PCM MIL driver failure

Diagnostic steps

  1. Check bulb during key-on bulb check
  2. Test MIL drive circuit from PCM
  3. Inspect cluster wiring
  4. Scan PCM for codes
  5. Test cluster LED

Repair notes

Replace MIL bulb/LED in cluster or repair wiring from PCM to cluster.

Other Body codes on this vehicle

๐Ÿ”ง Database maintained under the daily editorial review of Chris Hackleman ยท Master Technician ยท 20+ years and Jeff Moore ยท Master Mechanic ยท 20+ years. Spot an error? Use the Help link above โ€” a human reads every report.
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