Driver Door Ajar Circuit Malfunction
What does B1301 mean?
The B1301 code means the vehicle's onboard diagnostic system has detected: Driver Door Ajar Circuit Malfunction. This is a low severity code.
Common Symptoms
- Door ajar light stays on when door is closed
- Interior lights stay on while driving
- Dome light timeout not working
- Chime sounds as if door is open
- Remote start may not function
Probable Causes (Ranked by Likelihood)
- Faulty driver door ajar switch Very High
- Misaligned door latch not fully closing High
- Corroded door ajar switch connector Moderate
- Damaged wiring in driver door jamb Moderate
- BCM not properly reading door switch signal Low
Step-by-Step Diagnostic Procedure
-
Check if driver door is fully latching closed
-
Test door ajar switch with scan tool live data
-
Inspect door ajar switch in latch assembly
-
Check door jamb wiring for damage
-
Spray electrical contact cleaner into door latch mechanism
Frequently Asked Questions
Why does the door ajar light stay on?
The most common cause is a faulty door ajar switch inside the door latch. The switch sticks in the open position and falsely signals that the door is not fully closed.
Can I fix this with contact cleaner?
Sometimes. Spraying electrical contact cleaner into the door latch mechanism can free a stuck door ajar switch. If this works, the fix may be temporary and the switch may stick again.
Will this drain my battery?
Yes. If interior lights stay on because of a false door ajar signal, they can drain the battery if the vehicle sits for an extended period.