B2766

Code

Generic B — Body

Power Door Lock Control Circuit Fault (Front Passenger Door)

Brand: Generic

Type: B — Body

Views: UK: 7 EN: 9 RU: 9

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open or shorted wiring in the front passenger door lock circuit
Corroded, loose or damaged connector at the door hinge or actuator
Failed door lock actuator (motor or internal switch)
Faulty door module or body control module (BCM) output driver
Blown fuse or failed relay supplying the lock circuit
Water intrusion or rust in the door harness or actuator

Symptoms

Front passenger door will not lock or unlock with remote, master switch, or central locking
Intermittent or inconsistent operation of the passenger door lock
Audible clicking or no noise from actuator when lock command is given
Other doors may work normally while passenger door fails
Possible blown fuse or other related electrical issues

What to check

Verify DTC present with a scan tool and note freeze frame/occurrence
Operate lock from key fob, driver door switch, and passenger switch while observing behavior
Check related fuses and relays for continuity and proper operation
Visually inspect harness and connector at the passenger door hinge and actuator for damage or corrosion
Wiggle test the harness while cycling the lock to reproduce the fault
Measure voltage at the actuator connector while commanding lock/unlock

Signal parameters

Battery supply: ~12 V nominal at rest; should be ~11–14.5 V when tested under load
Actuator command: 0 V to ~12 V or polarity reversal depending on system (motor-driven locks may toggle polarity)
Typical actuator winding resistance: low ohms (commonly a few ohms up to ~20 Ω) — high or infinite indicates open circuit
When commanding lock/unlock expect a voltage or polarity change at the actuator connector concurrent with switch input
No excessive voltage drop (>1 V) between BCM output and actuator when commanded

Diagnostic algorithm

Record the DTC and any related codes. Clear codes, then attempt to re-run to confirm repeatability.
Confirm operation from multiple inputs (key fob, driver master switch, passenger switch). Note which inputs cause or fail to cause movement.
Check fuses/relays for the door lock circuit and replace if blown/faulty.
Visually inspect the door harness, especially at the hinge, for broken wires, rubbing damage, pinched sections, or water entry. Repair as needed.
Back-probe the actuator connector and command lock/unlock. Verify correct voltage/polarity and that voltage changes when commands are issued.
If no voltage change at actuator, trace back to door module/BCM: check continuity and resistance between actuator connector and module output. Repair open/shorts.
Test actuator resistance with the connector disconnected. If open or very high resistance, bench-test actuator with a 12 V supply to confirm operation; replace if faulty.
If actuator tests good and wiring checks out, test the door module/BCM output driver. Replace module only after confirming wiring and actuator good.
After repairs, clear DTC(s) and perform multiple lock/unlock cycles and a road/test cycle to ensure fault does not return.

Likely causes

Broken wires in the harness where it flexes at the door hinge
Connector pins pushed out, corroded, or contaminated at the actuator
Actuator motor seized or high resistance causing overcurrent
BCM or door module driver transistor shorted or open
Fuse for door locks blown or low battery voltage during operation
Moisture inside the door causing intermittent shorts

Fault status

⚠️ Status

Fault detected in front passenger door lock control circuit — possible open, short, poor connection, actuator failure, or control module output fault. Inspect wiring, connectors, actuator, fuses and module outputs.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours