Code Definition

B1402 — Driver Power Window Down Switch Circuit Failure

System: Body  |  Type: Manufacturer-Specific  |  Make: Generic

About B1402

B1402 is a manufacturer-specific body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B1402 is stored, the module has detected an electrical-circuit fault in the wiring, connector, or driver associated with the named component.

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.

B1402 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

The Body Control Module (BCM) or Door Control Module (DCM) sets B1402 when it detects a circuit failure on the driver power window down switch input. The module monitors the down switch contact through a pull up or pull down reference, expecting a defined voltage at rest and a different defined voltage when the switch is pressed; B1402 sets when the input reads stuck at one level, sits outside the calibrated range, or appears electrically illegal compared to the up switch state. Common causes include a stuck or worn switch contact in the master switch, a broken conductor through the door jamb ...

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