What Does B1326 Mean?
This code indicates the Body Control Module (BCM) has detected a short to ground in the door ajar warning lamp circuit. The BCM monitors the door ajar indicator lamp circuit and has identified that the circuit voltage is lower than expected, suggesting the circuit is grounded when it should not be. This prevents the door ajar lamp from functioning properly and may cause the lamp to stay illuminated continuously or fail to illuminate when doors are open.
Common Causes
45%
Damaged or chafed wiring between BCM and door ajar lamp with insulation worn through, causing wire to contact ground
30%
Failed door ajar lamp bulb socket with internal short to ground or corroded socket contacts
15%
Faulty Body Control Module with internal short circuit in lamp driver output
10%
Corroded or damaged connector terminals at BCM or instrument cluster allowing moisture intrusion and ground path
Diagnostic Steps
1
Step 1: Perform visual inspection of door ajar lamp bulb and socket in instrument cluster for signs of corrosion, melting, or damage. Remove bulb and inspect socket terminals for discoloration or shorts to ground.
2
Step 2: Using a digital multimeter, disconnect the BCM connector and measure resistance from the door ajar lamp control wire to chassis ground. Reading should be greater than 10,000 ohms; lower resistance confirms short to ground in wiring or lamp circuit.
3
Step 3: Disconnect the instrument cluster connector and repeat resistance measurement from BCM side of harness to ground. If resistance is now high (open circuit), the short is located in the instrument cluster or lamp socket. If still low resistance, short exists in body harness wiring.
4
Step 4: Inspect body harness routing between BCM and instrument cluster, paying special attention to areas where harness passes through metal panels, near door hinges, or under carpet where wiring may be pinched or chafed. Look for damaged insulation or wire strands touching metal.
5
Step 5: After locating and repairing short circuit, reconnect all components, clear code, and verify door ajar lamp operates correctly by opening doors while observing lamp function. Confirm no codes return after test drive.
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a short to ground in the door ajar warning lamp circuit. The BCM monitors the door ajar indicator lamp circuit and has identified that the circuit voltage is lower than expected, suggesting the circuit is grounded when it should not be. ...
The most common cause of B1326 (Door Ajar Lamp Circuit Short To Ground) is: Damaged or chafed wiring between BCM and door ajar lamp with insulation worn through, causing wire to contact ground
Typical repair costs for B1326 range from $75 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this only affects the door ajar warning lamp functionality. The primary concern is driver may not receive warning if doors are not properly closed, which could result in doors opening while driving. Repair at earliest convenience.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1326 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Body
System
Body Control and Warning Lamp System
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
