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!

Body generic / SAE

B0540

Driver Door Ajar Switch Circuit

The driver door ajar switch circuit is reporting an implausible signal. The interior light may stay on or door open warning may be incorrect.

SystemBody
Typegeneric / SAE
GroupB0
Range / number5 / 40

Possible causes

  • Corroded door switch / striker high
  • Wire break in door harness medium

Symptoms

  • Warning light or symbol related to the affected system
  • Comfort or safety function impaired

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 40–200 €
  • Estimated time: 0.4–1.5 h
  • Component: driver door ajar switch
  • Component: body control module

Sources

References

sae:J2012

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