OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

P0650

Malfunction Indicator Lamp Control Circuit Malfunction

A fault in the wiring or control circuit between the ECU and the malfunction indicator lamp (MIL). The MIL may stay on permanently, fail to light at key-on, or flicker — the OBD-II self-check on the bulb itself failed.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number6 / 50

Possible causes

  • MIL bulb burnt out (older clusters) medium
  • Instrument cluster MIL driver failed medium
  • Wiring fault between ECU and cluster low

Symptoms

  • Check engine light on
  • Possible limp mode or no-start
  • Multiple follow-up faults across modules
  • Reset/relearn may be needed after repair

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 50–600 €
  • Estimated time: 0.5–4 h
  • Component: mil lamp
  • Component: mil wiring
  • Component: instrument cluster
  • MIL / check engine light

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication