What does it mean?
B1320 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Driver Door Ajar Circuit Open .
Symptoms
- Interior lamps do not come on when the driver door is opened
- The door ajar warning never appears and the display always shows the door closed
- Key-in or door-open chime does not sound
- The alarm arms with the door open, or courtesy lamp timing is wrong
- Keyless entry and welcome lighting behave inconsistently
Likely causes
- Open circuit in the door ajar switch, which on most vehicles is built into the door latch
- Broken wire in the flexible loom at the door hinge, a classic failure caused by thousands of door openings
- Corroded or disconnected door jamb connector
- Latch switch contacts worn or packed with old grease
- Wiring damaged during door trim, speaker or mirror work
- Corrosion inside the latch after water leaked past the vapour barrier
- Body control module input stage failure
How to fix it
- Watch the driver door ajar input in live data while opening and closing the door
- Flex the loom inside the hinge boot while monitoring the signal for dropouts
- Peel back the rubber boot and inspect for broken or corroded strands
- Check the door jamb connector for pushed-back and corroded terminals
- Jumper the switch circuit to ground at the latch connector and see whether the module registers the change
- Replace the door latch assembly if the internal switch is open
- Repair the hinge harness, clear codes and confirm lamps, chimes and the alarm all behave correctly