DTC B13C3-29: Communication Error Between Body Control Module (BCM) And LF Control Unit (BCM) (Us): 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 B13C3:29 (BCM) (US) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Communication error between body control module (BCM) and LF control unit
Detection condition	The body control module (BCM) detects the communication error with the LF control unit 10 times.
Fail-safe	Inhibits the door lock/unlock control using the advanced keyless entry system.
Possible cause	LF control unit connector or terminal malfunction Body control module (BCM) connector or terminal malfunction Short to ground in LF control unit signal circuit Open circuit in LF control unit signal circuit LF control unit malfunction Body control module (BCM) malfunction
Courtesy of MAZDA MOTORS CORP.