What Does B1300 Mean?
B1300 indicates the Body Control Module (BCM) has detected an electrical fault in the power door lock circuit. This code is triggered when the BCM identifies abnormal voltage, current draw, resistance, or communication issues within the door lock actuator circuit. The system may experience intermittent or complete failure of one or more door locks to operate via the remote, switch, or key fob.
Common Causes
40%
Faulty door lock actuator with internal short, open circuit, or mechanical binding causing excessive current draw
30%
Damaged, chafed, or corroded wiring harness in door jamb area from repeated flexing
20%
Failed door lock switch or driver's master control switch with internal contact failure
10%
Body Control Module internal relay or driver circuit failure
Diagnostic Steps
1
Step 1: Perform visual inspection of all door lock actuators by removing interior door panels and checking for physical damage, binding, or disconnected linkage rods. Listen for abnormal noises during lock/unlock operation.
2
Step 2: Using a digital multimeter, backprobe the affected door lock actuator connector while commanding locks to operate. Verify 12V supply voltage present and check for proper ground continuity (less than 0.5 ohms to chassis ground).
3
Step 3: Disconnect each door lock actuator one at a time and monitor current draw using ammeter while commanding lock operation. Normal draw should be 3-8 amps; excessive draw (over 10 amps) indicates faulty actuator motor.
4
Step 4: Inspect door jamb wiring harness for chafing, breaks, or corrosion by flexing wires while monitoring circuit continuity with multimeter. Check connector terminals for corrosion, bent pins, or loose fit.
5
Step 5: Test door lock switches by measuring continuity and resistance across switch terminals during operation. Expect near-zero ohms when activated and infinite resistance when released.
6
Step 6: After repairs, clear codes, cycle all door locks 10-15 times using multiple methods (key fob, switch, manual), then verify code does not return and all locks operate smoothly.
Estimated Repair Cost
$120 - $650
Parts + labor, varies by vehicle and location
B1300 indicates the Body Control Module (BCM) has detected an electrical fault in the power door lock circuit. This code is triggered when the BCM identifies abnormal voltage, current draw, resistance, or communication issues within the door lock actuator circuit. The system may experience intermitt...
The most common cause of B1300 (Power Door Lock Circuit Failure) is: Faulty door lock actuator with internal short, open circuit, or mechanical binding causing excessive current draw
Typical repair costs for B1300 range from $120 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This code does not affect vehicle drivability or safety systems and it is safe to continue driving. However, security may be compromised if doors cannot lock properly, and vehicle theft risk increases until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1300 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Security System
Difficulty
Type
Manufacturer
Recommended Tools
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