Code Definition

B2124 — Door Passenger Reset Switch Stuck Failure

System: Body  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About B2124

B2124 is a generic (obd-ii standard) body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

Because B2124 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

B2124 is set when the body control module (BCM) detects that the passenger door reset switch input has remained in the active or closed state continuously beyond the expected time window, indicating a stuck switch failure. The door reset switch provides a discrete signal to the body control module that is used to confirm door closure and to control body system functions such as door ajar warning, interior courtesy lighting timing, perimeter alarm arming, and lock or unlock automation. When the body control module sees a constant active signal that does not change in response to expected door o...

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