LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2020 >> CX-3 AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> On-Board Diagnostic - Advanced Keyless Entry System >> DTC B13C3-09: LF Control Unit Malfunction (Advanced Keyless Entry System) >> Notes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC B13C3-09: LF Control Unit Malfunction (Advanced Keyless Entry System): Notes

DTC B13C3:09 (ADVANCED KEYLESS ENTRY SYSTEM) DETECTION CONDITION AND POSSIBLE CAUSE

Description LF control unit malfunction
Detection condition
  • When any of the following conditions is met:
    • Start stop unit detects that the LF state signal of the LF control unit is low for 5 s or more.
      • With the communication between the start stop unit and LF control unit being performed normally, there is no response from the LF control unit even though there is the signal transmission request from the start stop unit to the LF control unit, and the LF state signal becomes low.
Fail-safe
  • Inhibits the door lock/unlock control using the advanced keyless entry system.
Possible cause
  • LF control unit connector or terminal malfunction
  • Start stop unit connector or terminal malfunction
  • Short to ground in wiring harness between start stop unit terminal 2H and LF
  • control unit terminal G
  • Open circuit in wiring harness between start stop unit terminal 2H and LF control unit terminal G
  • LF control unit malfunction
  • Start stop unit malfunction
G13151794Courtesy of MAZDA MOTORS CORP.