Code
B1396
ALFA ROMEO
B — Body
Electric door closing circuit short to positive
Views:
UK: 3
EN: 9
RU: 5
AI status
Completed
Completed
100%
Causes
- Chafed or pinched wiring in the door harness contacting a positive feed
- Water ingress or corrosion at door connectors or actuator
- Shorted actuator (internal motor or diode failure)
- Aftermarket alarm/remote wiring incorrectly connected
- Faulty door control module or BCM driver transistor
- Broken or bent connector pins creating unintended positive feed
Symptoms
- Central locking/door closing does not operate or operates unpredictably
- Blown fuse(s) on the locking/door circuit
- Intermittent operation of lock/unlock or constant lock command
- Battery drain or parasitic draw when vehicle is off (if circuit remains powered)
- Fault indicator or message related to door lock/closure system
What to check
- Read and record all stored body module/BCM codes and freeze frame data
- Visual inspection of door harness, rubber boot/hinge area for chafes, pinches, water damage or broken wires
- Inspect connectors at door latch/actuator and body side for corrosion, bent pins or moisture
- Check related fuses and fusible links for continuity and correct rating
- Operate locks while watching actuator and circuit voltage (use a scan tool or multimeter)
- Disconnect door actuator/connector — clear DTCs and re-run test to see if fault returns (isolates actuator vs harness/module)
Signal parameters
- Resting driver output voltage (should be ~0–1 V when not commanded)
- Commanded driver output ~battery voltage (≈12–14 V) when actuator is intentionally driven
- If short-to-positive fault present: measured voltage at actuator connector shows battery voltage when no command is present (~12 V)
- Typical actuator coil resistance (varies by design) commonly in the range ~5–40 Ω; open circuit indicates broken coil, very low/near 0 Ω can indicate internal short
- Activation current: actuator pulses can draw up to several amps (typically 1–10 A) — use a clamp ammeter if available
Diagnostic algorithm
- Record DTC B1396 and any related codes; note conditions (ignition state, door position).
- Visually inspect door wiring, rubber boot and connectors for damage, corrosion or moisture. Repair any obvious wiring damage. Disconnect battery before cutting/repairing wires.
- Check fuses and relays for the door/lock circuit; replace any blown fuses and re-test. If fuse blows again, further isolation required.
- With ignition on, backprobe the actuator connector. Command the lock/unlock and observe voltages. Note if battery voltage is present with no command (indicates short to positive).
- Disconnect the actuator connector. Clear codes and re-check operation: if the DTC no longer sets, fault is in actuator or downstream wiring; if it remains, suspect body module/BCM or feed wiring on vehicle side.
- Perform continuity and short-to-power checks: with connector disconnected, check for continuity between the actuator output pin and battery positive. Use an ohmmeter and verify insulation to chassis ground. Locate and repair any shorted section (commonly in hinge/boot area).
- If wiring and connectors are good and actuator is disconnected yet fault persists, test/replace the door control module/BCM driver or consult module bench test procedures. Consider comparing driver output to a known-good module or using an oscilloscope to check driver behavior.
- After repair, reassemble trim, secure harness, reconnect battery, clear DTCs and perform several lock/unlock cycles to ensure the fault does not return. Monitor for parasitic draw if battery issues were present.
Likely causes
- Damaged/abraded wiring in hinge/boot area shorting to battery positive (most common)
- Failed door lock actuator motor with internal short to battery
- Corroded/bridging connector at door latch or body harness
- Incorrectly wired aftermarket device (alarm/remote)
- Driver transistor failure inside the door module/BCM
Fault status
Status
B1396 — Electric door closing circuit short to positive. Short to battery detected on door/lock actuator circuit.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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