B1396

Code

Other B — Body

Power Door Lock Circuit Short To Battery

Brand: Other

Type: B — Body

Views: UK: 23 EN: 39 RU: 26

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Wiring shorted to constant battery feed (chafed/harness pin contacting a 12V source)
Shorted or stuck door lock actuator (internal short to battery)
Aftermarket alarm or remote lock/remote start incorrectly wired to door lock circuit
Faulty door lock relay stuck closed
Body control module (BCM) / door module driver failure
Corroded or damaged connector allowing battery voltage to leak into circuit

Symptoms

Door locks do not respond to lock/unlock commands or operate erratically
One door locks/unlocks by itself or remains locked/unlocked
Associated fuse(s) blow repeatedly
Battery drain or parasitic draw related to lock circuit
Stored related DTC(s) and possible reduced functionality of central locking

What to check

Scan for B1396 and any related codes; note occurrence count and freeze frame data
Visually inspect wiring harnesses and connectors at doors, door jambs, and the BCM for damage or corrosion
Check for aftermarket alarm/remote modules and verify wiring is correct
Inspect relevant fuses and relays for the door lock circuit
Backprobe and measure voltage at door lock actuator connector with ignition OFF and with commands
Unplug individual door actuators or remove door module connectors to see if code clears or symptoms change

Signal parameters

Battery voltage reference: ~12.0–14.5 V (with engine running: 13.5–14.5 V)
Expected lock driver output when inactive: open circuit or 0 V (no battery feed present)
Expected lock driver output when commanded: pulsed or switched voltage to actuator (varies by vehicle)
Actuator coil resistance (typical): about 5–50 ohms (varies by design)—compare to factory spec
If short to battery present: measured voltage on lock control wire ~battery voltage (~11–14 V) even when no command is given

Diagnostic algorithm

Read and record codes and freeze frame data with a scan tool. Note affected door(s) and occurrence conditions.
Visually inspect connectors, wiring looms and door harness rub points (hinge area) for damage, pin shorts, corrosion, or water ingress.
Disconnect any aftermarket alarm/remote locking module or verify its wiring is not tied to a constant 12V feed on the lock circuit.
With ignition OFF, access the suspected door lock connector and measure voltage to ground on the lock control pins. A steady ~12V with no command indicates a short to battery.
Unplug the door lock actuator/door module connector. If the DTC clears or the short disappears when disconnected, suspect the actuator or door harness. If the short remains with actuator disconnected, suspect wiring upstream or BCM.
Perform a wiggle test of the harness while monitoring voltage and scan tool data to find intermittent shorts caused by movement.
If wiring short location is not obvious, isolate sections of the circuit: disconnect at junctions, remove interior panels to trace harness, and use a short locator or ohmmeter to find continuity to battery where it should not exist.
Inspect and test lock/unlock relay(s) and fuses; replace if stuck or damaged.
If wiring and actuators check OK, test BCM output driver: measure output pin behavior while commanding locks. If BCM output is defective (stuck high) replace or reprogram BCM per manufacturer procedures.
Repair or replace faulty wiring, actuator, relay, or BCM as indicated. Reassemble, clear codes, and verify proper operation through multiple lock/unlock cycles and road/test conditions.

Likely causes

Harness chafing where lock switch/actuator wiring contacts a constant 12V wire (most common)
Door lock actuator motor internally shorted to 12V
Aftermarket alarm/remote wiring tied incorrectly to the lock feed
Stuck or welded relay in lock/unlock relay assembly
Faulty BCM driver pin output or internal short

Fault status

⚠️ Status

Power door lock circuit detected short to battery voltage. Investigate wiring, actuator, relays and control module. Repair required to restore proper lock control and prevent blown fuses or battery drain.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours