Code
B29DA
MITSUBISHI
B — Body
Rear center latch:open cycle
Views:
UK: 8
EN: 15
RU: 12
AI status
Completed
Completed
100%
Causes
- Faulty rear center latch assembly (mechanical binding or failed position switch)
- Damaged or corroded wiring or connector to the latch
- Failed latch actuator (motor/solenoid)
- Intermittent or incorrect signal from body control module (BCM) or door ECU
- Foreign objects or ice/jam preventing latch movement
Symptoms
- Rear center door may not lock or unlock reliably
- Trunk/rear door status warning on dash or message
- Interior/exterior handle operation feels stiff or incomplete
- Alarm or central locking behaves erratically for rear center door
- DTC present and may reappear after clearing if underlying issue persists
What to check
- Scan vehicle to read freeze frame and related door/latch codes; note when code occurs
- Operate rear center latch while observing door status on scan tool or dash
- Visual inspection of latch, linkage, and surrounding area for damage, debris, corrosion, or ice
- Inspect connector at latch for corrosion, bent pins, or water intrusion
- Backprobe latch connector to monitor voltage and switch signal while operating latch
- Check continuity and resistance of wiring from latch back to BCM/door ECU
Signal parameters
- Latch position switch: toggles between two states when latch is cycled (closed vs open). Expect a clear state change when operated.
- Actuator supply: battery voltage present at actuator power feed during a lock/unlock command (approx. vehicle battery voltage).
- Switch continuity: open circuit in one position, closed (or low resistance) in the other; switch should change state immediately when latch moves.
- Signal timing: state change should occur within ~1 second of actuator movement/command.
Diagnostic algorithm
- Connect a capable scan tool and record stored B29DA and any related door/latch codes; view live data for rear center latch status while operating door.
- Reproduce the fault: operate the rear center door lock/unlock and observe whether the latch position indicator changes state. Note any delay or failure to change.
- Perform a visual inspection of the latch, actuator and linkage for mechanical binding, broken parts, foreign objects, or corrosion; free any obstruction and retest.
- Inspect and clean the latch connector; check for bent pins, corrosion, or water ingress. Wiggle the harness while observing live data to detect intermittent faults.
- Backprobe the latch connector and measure: a) supply voltage to actuator during command, b) latch position switch signal while cycling. Compare to expected state changes.
- Check continuity between latch connector and BCM/door ECU connector for opens/shorts; repair any damaged wiring or poor terminations.
- If actuator receives proper power but latch does not move, remove and bench-test or replace the latch assembly (including switch).
- After repairs, clear diagnostic trouble codes and perform multiple open/close cycles to confirm the fault does not return and that live data shows correct switching.
Likely causes
- Latch position switch stuck or worn (no change of state during operation)
- Connector pins corroded or loose at latch harness
- Broken wire or short to ground/power in latch circuit
- Actuator receives power but mechanical linkage is disconnected or seized
- Water ingress causing intermittent signal
Fault status
Status
Rear center latch: open cycle detected — latch position signal did not complete expected open/close sequence.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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