B2602

Code

Other B — Body

Missing Latch Signal During Power Sliding Door Unlatch

Brand: Other

Type: B — Body

Views: UK: 17 EN: 38 RU: 29

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Open, shorted or intermittent wiring between latch and body control module (BCM)
Corroded or loose connector at latch or BCM
Faulty latch position switch or sensor
Failed latch actuator or internal latch assembly fault
Blown fuse or loss of power/ground to latch circuit
Mechanical binding or misadjusted striker preventing latch movement

Latch switch is typically a digital feedback (open/closed) to the BCM — expect the state to toggle when unlatch command is issued
Typical feedback voltage: near battery voltage (approx. 12V) or 0V depending on circuit design, or a 0–5V logic signal on some vehicles
Latch actuator coil resistance: usually low (a few ohms to a few tens of ohms) — consult vehicle-specific data
No high-resistance or open-circuit should be present in the feedback wire when operated

Connect scan tool, confirm B2602 and view live data for latch position/feedback while operating the sliding door from each command source (interior switch, exterior handle, remote).
Perform a visual inspection of the latch assembly, connector, and wiring for damage, corrosion, or water entry. Repair or secure any issues found.
With connector connected, backprobe the latch feedback pin. Command the system to unlatch and observe the feedback signal change. If no change, proceed.
Verify power and ground at the latch connector. With door unlatch commanded, check for proper supply voltage to the actuator or reference voltage to the sensor.
Measure continuity between the latch connector and the BCM input pin to rule out open circuits. Check for shorts to power or ground.
Measure resistance of the latch actuator/sensor (with power removed). Compare to spec if available. An open or out-of-range value suggests a faulty latch assembly.
If wiring and latch assembly test good but no feedback, check BCM output/inputs for proper operation. Perform connector cleaning and repair any damaged wiring before replacing modules.
Replace the latch assembly if tests indicate internal switch or actuator failure. After repairs, clear codes and verify proper operation through multiple cycles.
If fault persists after latch replacement and harness is good, consider BCM diagnosis or replacement following vehicle manufacturer procedures.