DTC B1D39-12: Rear Wiper Motor Circuit Malfunction (BCM): Outline

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

DTC B1D39:12 (BCM) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Rear wiper motor circuit malfunction
Detection condition	The electrical supply unit (ESU) detects a short to power supply in the rear wiper motor circuit. Preconditions Rear wiper switch position is ON.
Fail-safe	Not applicable
Possible cause	Rear wiper motor connector or terminal malfunction Electrical supply unit (ESU) connector or terminal malfunction Short to power supply in rear wiper motor signal circuit (motor) Rear wiper motor malfunction Electrical supply unit (ESU) malfunction Body control module (BCM) malfunction
Courtesy of MAZDA MOTORS CORP.