What Does B1565 Mean?
This code indicates the Body Control Module (BCM) has detected a short to battery voltage in the door ajar circuit. The door ajar switch or its wiring is receiving constant 12V power when it should only see voltage during specific conditions. This causes the vehicle to think a door is always open, triggering interior lights, warnings, and potentially preventing proper security system operation.
Common Causes
45%
Damaged or chafed wiring in door jamb area causing short to power wire
30%
Failed door ajar switch with internal short to voltage
15%
Water intrusion or corrosion in door ajar switch connector causing cross-circuit short
10%
BCM internal fault or connector corrosion at BCM causing false short detection
Diagnostic Steps
1
Step 1: Visually inspect door jamb wiring harness on all doors for chafing, pinching, or damaged insulation where wires flex during door opening/closing. Look for exposed copper or wire damage near hinges.
2
Step 2: Disconnect the door ajar switch connector and measure voltage at the BCM side of the harness connector using a digital multimeter. Should read 0V with switch disconnected; if 12V is present, wiring harness has short to power.
3
Step 3: If no voltage found in Step 2, check resistance of door ajar switch itself. Should show open circuit (infinite resistance) when door is closed and continuity to ground when activated. Replace switch if it shows continuity to battery voltage.
4
Step 4: Inspect BCM connector pins for corrosion, bent pins, or moisture intrusion. Clean or repair connector as needed. If all wiring and switches test good, BCM may have internal fault.
5
Step 5: After repair, clear codes and cycle all doors open and closed multiple times while monitoring live data for proper door ajar status changes. Verify interior lights and warning messages operate correctly.
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 battery voltage in the door ajar circuit. The door ajar switch or its wiring is receiving constant 12V power when it should only see voltage during specific conditions. This causes the vehicle to think a door is always open, t...
The most common cause of B1565 (Door Ajar Circuit Short To Battery) is: Damaged or chafed wiring in door jamb area causing short to power wire
Typical repair costs for B1565 range from $75 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive but interior lights may stay on draining the battery, security system may not arm properly, and door ajar warnings will be constant. Address within a few weeks to prevent battery drain issues.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1565 to identify the root cause.
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Quick Info
Category
Body
System
Body Control System
Difficulty
Type
Manufacturer
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