LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2021 >> 3 Select, 4D Hatchback, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> On-Board Diagnostic - Body Control Module (BCM) (1 Of 2) >> DTC B13C3-29: Communication Error Between Body Control Module (BCM) And LF Control Unit [(BCM)] >> Outline
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC B13C3-29: Communication Error Between Body Control Module (BCM) And LF Control Unit [(BCM)]: Outline

DTC B13C3:29 (BODY CONTROL MODULE) 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.
  • Cancel the i-stop control.
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
G13716775Courtesy of MAZDA MOTORS CORP.