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Home >> Mazda >> 2024 >> MX-5 Miata Club >> Repair and Diagnosis >> Accessories & Equipment >> Drivers Assistance Systems - ADAS >> On-Board Diagnostic - Vehicle Control Module (1 Of 2) >> DTC U0401-68: Error Signal Received From Pcm, DSC HU/Cm, Instrument Cluster, Or Body Control Module (BCM)
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DTC U0401-68: Error Signal Received From Pcm, DSC HU/Cm, Instrument Cluster, Or Body Control Module (BCM)

U0401-68: (VCM) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location Error signal received from PCM, DSC HU/CM, instrument cluster, or body control module (BCM)
Detection condition
  • When any of the following conditions is met.
    • The vehicle control module (VCM) receives the error signal from the PCM.
    • The vehicle control module (VCM) detects that the brake signals between the following modules did not match while the brake pedal is operated.
      • PCM
      • DSC HU/CM
      • Body control module (BCM)
    • The vehicle control module (VCM) detects that a fail-safe is operated based on a deceleration request while the vehicle is being driven.
Fail-safe (See DTC TABLE [VCM] .)
Possible cause
  1. Internal malfunction related DTCs are stored in the following modules.
  2. DTCs are stored in the following modules.
  3. Cruise control switch malfunction (Refer to CRUISE CONTROL SWITCH INSPECTION in service information.)
  4. PCM malfunction (Refer to PCM INSPECTION [SKYACTIV-G 2.0] in service information.)
  5. DSC HU/CM malfunction (Refer to DSC HU/CM INSPECTION in service information.)
  6. Vehicle control module (VCM) malfunction (built-into body control module (BCM)) (Refer to BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION in service information.)
Repeatability verification procedure
  1. Clear the DTC recorded in the memory. (See CLEARING DTC .)
  2. Operate the brake pedal.
System wiring diagram
  • Not applicable