B1329: Passenger Door Ajar Circuit Short to Battery
The B1329 code indicates that the vehicle's control module has detected a short to battery positive in the passenger door ajar sensor circuit. This circuit monitors whether the door is open or closed via a switch that changes state when the door is opened or closed. A short to battery means the circuit is receiving constant voltage when it shouldn't, causing the module to misinterpret the door status or detect an anomalous signal. This code is specific to Ford Motor Company and its associated brands, where the 'B' prefix indicates a body and comfort system fault.
1. Commonly Affected Makes
2. Most Common Causes
- Passenger door ajar sensor wiring shorted to battery positive
- Damaged or stuck-closed passenger door ajar switch
- Corroded or bent pins in the door sensor connector causing contact with power
- Body control module (GEM/SJB) internal fault misinterpreting the signal
- Damaged wiring splice or harness in the B-pillar or passenger door conduit
3. Symptoms You Will Notice
- Door ajar warning light or message on the dash for the passenger door
- Interior dome light stays on or behaves erratically
4. Step-by-Step Diagnosis
Scan for additional codes and verify B1329 is present
Visually inspect passenger door ajar switch wiring and connector for damage, corrosion, or shorts to battery
Test the door ajar switch operation with a multimeter; check for continuity when door is open and closed
Check for battery voltage on the signal wire when the door is closed (should be low/ground)
If wiring and switch are okay, suspect a faulty body control module (GEM/SJB)
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive with this code, but the door ajar warning may be distracting and the interior lights may stay on, draining the battery. It is recommended to diagnose and repair the issue soon.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on the cause. A simple switch replacement may be $50-$150, while wiring repairs or module replacement can be $200-$400 or more.