Code Definition

B1421 — Passenger Power Window Motor Circuit Short To Ground

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

About B1421

B1421 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 B1421 is stored, the module has detected a short-circuit (voltage pulled to ground or to supply) in the monitored circuit.

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.

B1421 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) monitors the power window motor control circuits to detect electrical faults that could cause unsafe operation or motor damage. DTC B1421 is set when the module detects a short to ground condition on the passenger window motor circuit, meaning the circuit is being pulled to chassis ground when it should be either floating, supplied from the module driver, or open. The passenger window motor is normally driven by reversible polarity from BCM or door module driver outputs that are switched to ground or battery as needed for up and down o...

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