Driver Door Switch Circuit Fault
The B1319 code indicates that the Body Control Module (BCM) or Smart Junction Box (SJB) has detected a fault in the driver door open switch circuit. This can be caused by a short to ground, short to voltage, open circuit, or a stuck/invalid switch state, preventing the module from accurately determining the door position.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty or stuck door open switch (integrated into the latch assembly)
- Damaged, cut, or shorted wiring in the door jamb harness boot
- Corroded, loose, or pushed-out terminals at the latch or BCM/SJB connectors
- Internal failure of the Body Control Module (BCM) or Smart Junction Box (SJB)
- Mechanical misalignment of the door or latch preventing proper switch activation
3. Symptoms You Will Notice
- Door ajar warning light stays on or off incorrectly
- Interior dome light fails to turn on/off with door
- Power locks or alarm system may not function properly
- Possible battery drain if module stays awake
4. Step-by-Step Diagnosis
Inspect the door jamb wiring harness for breaks, chafing, or corrosion, especially near the hinge area.
Test the door switch operation using a scan tool to monitor the door status signal.
Check for voltage, ground, and continuity at the switch connector; compare with known good values.
If wiring and switch test OK, suspect a BCM/SJB fault and perform module self-test or replacement.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is generally safe to drive, but you may experience minor electrical issues like a false door ajar warning or interior lights not working. It is recommended to diagnose and repair the fault to prevent potential battery drain.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on the cause. A simple switch replacement may cost $50-$150, while wiring repairs or BCM replacement can be $200-$600 or more.