Obdaryn

B0541Passenger Door Ajar Switch Circuit

  • Generic OBD-II code · Body
How the car detects it
B0541 cannot be traced in public J2012 lists or published manufacturer data. By its title it covers the ajar switch circuit of the front passenger door. Saab's 9-3 monitors that switch as B2991 in the body control module using the driver-side thresholds: 02 for a grounded line under 2.9 V, 05 for an open line or battery short over 10.2 V. Many modern doors have no separate jamb plunger; ArvinMeritor's US20030182863A1 puts the ajar switch on the latch claw, where it changes state roughly halfway between the fully latched and the safety position, so a door that only reached the safety catch still reads as ajar. A latch replacement can therefore be the fix. Driver side: B0540.
What you may notice
  • Passenger door reported open while driving
  • Courtesy light does not react to the passenger door
  • Alarm cannot be armed or triggers falsely
Likely causes
  • LikelyAjar switch inside the passenger door latch worn
  • PossibleDoor only reaching the safety catch due to misaligned striker
  • PossibleSwitch wire open or grounded in the hinge passage
  • RareBody control module input faulty
Repair
Easy · Often possible to do yourself.Typical cost: €40 – €300
Related codes

Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.