B2104

Door Passenger Key Cylinder Switch Failure

Severity

✅ Low

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$22–111 (est.)

Symptoms

False alarm about an open door
Inability to unlock the door with a key
Comfort closing/opening functions do not work
The door ajar indicator lights up when the door is closed

Causes

Oxidation or wear of limit switch contacts
Broken wires in the harness between the lock and the control unit
Short circuit in the limit switch circuit
Door control unit malfunction

How to Fix

Check the operation of the limit switch with a multimeter
Inspect the wiring harness for damage
Clean the switch contacts from oxides
If necessary, replace the limit switch or wiring harness
Reset the error code and check if it appears again

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