B1301

Code

Other B — Body

Power Door Lock Circuit Open

Brand: Other

Type: B — Body

Views: UK: 16 EN: 39 RU: 28

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Page language: EN

Causes

Open or broken wiring in the door lock circuit
Blown fuse or faulty relay for door locks
Corroded or loose connector at door, actuator, or module
Failed door lock actuator or lock motor
Faulty door lock switch or keyless entry module
Defective body control module (BCM) or driver transistor

Symptoms

Door lock(s) do not lock or unlock with key, switch or remote
Intermittent lock operation that works when door is wiggled
Only some doors respond while others do not
No voltage present at actuator connector when lock/unlock commanded
Related door lock fault indicator or message on instrument cluster

What to check

Retrieve freeze frame and live data with a scan tool; confirm B1301 and any related codes
Visually inspect fuses and relays for the door lock circuit
Inspect connectors at door hinges, actuator and BCM for corrosion, damage or loose pins
Backprobe actuator connector and check for voltage while commanding lock/unlock
Measure actuator coil resistance and continuity to BCM
Perform wiggle test on harness while operating locks to detect intermittent opens

Signal parameters

Rest voltage at actuator connector: ~0 V (no command); command voltage: near battery voltage (~11–14 V) on the supply pin when activated
Return/ground pin should be near 0 V when commanded (or switch between supply and ground depending on driver design)
Typical actuator coil resistance: usually between 5–50 ohms (varies by make/model) — an open reads OL/infinite
Continuity from BCM output pin to actuator connector: near 0 ohms (allowing harness length resistance)
If PWM-driven, frequency and duty cycle vary by manufacturer; expected is a pulsed signal only when locking/unlocking

Diagnostic algorithm

Connect a scan tool and confirm B1301 is present; note freeze-frame conditions and any companion codes.
Operate door lock using switch, remote, and scan-tool command while observing which doors respond.
Inspect fuses and relays related to door locks; replace any blown fuse and retest.
Visually inspect wiring and connectors at the affected door jambs and actuator; repair any visible damage or corrosion.
Backprobe the actuator connector. Command lock/unlock and verify presence of correct voltage or switching signal at the appropriate pins.
Measure actuator coil resistance with connector disconnected. If open or out-of-spec, replace actuator or bench-test it.
Check continuity between the BCM (or module output pin) and the actuator connector. Repair any open wiring or poor terminals.
Verify grounds for the door/BCM circuit are clean, tight and low-resistance.
If wiring and actuator are good but no output is present, test the BCM output driver (per manufacturer procedure) or swap with known-good channel if possible.
Repair or replace faulty components (wiring, connector, actuator, switch, relay, BCM). Reassemble, clear codes and retest all functions until code does not return.
If intermittent, perform road/usage test and wiggle harness to confirm repair; re-scan to ensure no latent faults remain.

Likely causes

Open/disconnected connector at the affected door actuator
Blown fuse protecting the door lock circuit
Broken wire in the harness between BCM and door actuator (common at hinge/door jamb)
Failed actuator coil (high resistance/open) on the affected door
Corroded pins causing loss of continuity to the actuator
BCM output driver failed (no voltage output when commanded)

Fault status

⚠️ Status

Stored when the control unit detects an open (no continuity or no voltage output) in the power door lock circuit. May be set as active (current) or historic; corroborate with live data and operation tests before repair.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours