B24B0

Code

Generic B — Body

Left rear door lock actuator circuit malfunction

Brand: Generic

Type: B — Body

Views: UK: 10 EN: 25 RU: 7

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Page language: EN

Causes

Failed left rear door lock actuator (mechanical or electrical failure)
Broken, chafed, pinched, or corroded wiring in the door harness
Poor or corroded connector pins at the actuator or BCM
Bad ground or power supply to the actuator
Blown fuse or faulty relay feeding the door lock circuit
Faulty door lock switch or sensor

Symptoms

Left rear door fails to lock or unlock with key fob, door switch, or central locking
Intermittent operation of left rear door lock
Audible clicking or humming at the door when attempting to lock/unlock
Other doors operate normally
Possible blown fuse or triggered circuit protection

What to check

Visual inspection of left rear door, actuator, connectors, and wiring for damage, corrosion, or water
Check fuse(s) and any applicable relays for the locking circuit
Attempt to operate lock while observing connector and wiring for movement-induced faults
Use a scan tool to command the left rear door lock and monitor BCM status/messages
Measure voltage at the actuator connector while commanding lock/unlock
Check continuity and resistance of actuator wiring to the BCM

Signal parameters

Supply voltage at actuator while commanded: ~11–14 V (12 V system)
Rest voltage at actuator connector (uncommanded): 0–12 V depending on circuit design
Typical actuator coil resistance (varies by design): ~10–60 ohms (measure expected spec from service data)
Actuator current draw while operating: commonly 0.5–3 A (can spike higher briefly)
Command pulse duration: often 0.5–2.0 seconds for lock/unlock actions (varies by vehicle)

Diagnostic algorithm

Retrieve freeze frame/live data and any related codes with a diagnostic scanner; note whether the fault is open, short to ground, short to voltage, or high/low current.
Perform a visual inspection of the left rear door area: check for water, corrosion, damaged harness, crushed wires at the door hinge/boot, and connector condition.
Verify fuse(s) and relays for the door lock circuit. Replace if blown or suspect.
With connector disconnected, measure resistance of the actuator (compare to service spec). Very high/OL or very low indicates a bad actuator.
Backprobe the actuator connector while commanding lock/unlock: verify correct supply voltage(s) and switching to ground or opposite polarity as expected. Note any missing pulses or abnormal voltages.
Check continuity from the actuator connector pins back to the BCM or door module; check for shorts to ground or battery and for high resistance/opens.
Verify ground integrity at the door ground point with a load/voltage drop test while operating the lock.
If wiring and power/ground are good but actuator fails, swap in a known-good actuator or temporarily apply bench 12 V to the actuator to confirm operation (exercise caution to avoid damage).
If actuator works but BCM output is not providing proper drive signals, inspect for BCM/door module faults, update software if applicable, and consider module repair/replacement only after wiring and actuator are proven good.
Clear trouble codes and perform repeated function tests to confirm repair; verify no new or recurring related codes.