What Does B1310 Mean?
B1310 indicates the Body Control Module (BCM) has detected a malfunction in the power door unlock circuit. This means the BCM is unable to properly control or receive feedback from the door unlock relay, actuators, or associated wiring. The system may fail to unlock doors electrically via key fob, interior switches, or automatic unlocking features.
Common Causes
35%
Faulty door lock actuator or internal actuator motor failure causing excessive current draw or open circuit
30%
Damaged wiring harness or corroded connectors in door jamb between body and door causing intermittent or open circuit
20%
Failed door lock relay or relay control circuit in BCM or junction box
10%
Internal BCM fault or corroded BCM connector terminals affecting unlock circuit control
5%
Blown fuse or fusible link in the door unlock power supply circuit
Diagnostic Steps
1
Step 1: Verify fuse integrity in the power door lock circuit using a test light or multimeter, checking both sides of fuse for 12V with ignition on. Replace if blown and retest system.
2
Step 2: Access door lock actuator connector at affected door and measure voltage at unlock wire while activating unlock function (should see 12V pulse). If no voltage, trace back to BCM; if voltage present, suspect actuator.
3
Step 3: Perform resistance test on door lock actuator motor by measuring between power and ground terminals (typically 3-20 ohms). Out-of-range readings indicate failed actuator.
4
Step 4: Inspect door jamb wiring harness for broken wires, chafing, or corroded pins by flexing harness while monitoring continuity with multimeter. Check all connector terminals for corrosion and clean as needed.
5
Step 5: Test door lock relay operation by swapping with identical relay or manually jumping relay terminals to verify actuator function. Listen for relay click when unlock is commanded.
6
Step 6: Clear codes and perform functional test of all door unlock operations (key fob, interior switch, driver door). Monitor live data for BCM unlock circuit feedback to confirm repair.
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
B1310 indicates the Body Control Module (BCM) has detected a malfunction in the power door unlock circuit. This means the BCM is unable to properly control or receive feedback from the door unlock relay, actuators, or associated wiring. The system may fail to unlock doors electrically via key fob, i...
The most common cause of B1310 (Power Door Unlock Circuit Failure) is: Faulty door lock actuator or internal actuator motor failure causing excessive current draw or open circuit
Typical repair costs for B1310 range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this is a convenience feature failure. However, compromised security due to inability to lock/unlock doors electrically may require manual key operation and should be repaired within a reasonable timeframe.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1310 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Convenience Systems
Difficulty
Type
Manufacturer
Recommended Tools
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