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Home >> Mazda >> 2024 >> CX-30 Premium >> Repair and Diagnosis >> Accessories & Equipment >> Headlights >> On-Board Diagnostic - Adaptive Front Lighting System Control Module >> DTC U2121-87: Communication Error With Vehicle Control Module (VCM) [Adaptive Front Lighting System (AFS) Control Module]
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DTC U2121-87: Communication Error With Vehicle Control Module (VCM) [Adaptive Front Lighting System (AFS) Control Module]

U2121: 87 (ALH/AFS/ALV) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location Communication error with vehicle control module (VCM)
Detection condition
  • The adaptive LED headlights control module cannot receive CAN signal from the vehicle control module (VCM).
Fail-safe
  • Control of the headlight auto leveling system is continued.
  • Perform the following controls with the adaptive LED headlights turned on.
    • Turn off glare-free high beam.
    • Set wide-range low beam as basic light distribution.
Possible cause
  1. Malfunction in CAN communication line between vehicle control module (VCM) and adaptive LED headlights control module
NOTE:
Repeatability verification procedure
  • Not applicable
System wiring diagram
  • Not applicable