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Home >> Mazda >> 2021 >> 3 Select, 4D Hatchback, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Collision/Avoidance >> On-Board Diagnostic - Vehicle Control Module (2 Of 2) >> DTC U0156-00: Communication Error With Connectivity Master Unit (CMU) [Vehicle Control Module] >> Outline
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DTC U0156-00: Communication Error With Connectivity Master Unit (CMU) [Vehicle Control Module]: Outline

DTC U0156:00 [VEHICLE CONTROL MODULE] DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location Communication error with connectivity master unit (CMU)
Detection condition
  • The vehicle control module (VCM) cannot receive CAN signal from connectivity master unit (CMU) for 10 s.
Fail-safe (See DTC TABLE [VEHICLE CONTROL MODULE (US)] .)
Possible cause
  • Malfunction in CAN communication line between vehicle control module (VCM) and connectivity master unit (CMU)
  • Connectivity master unit (CMU) malfunction
  • Vehicle control module (VCM) malfunction (built into body control module (BCM))
  • Body control module (BCM) malfunction
System wiring diagram Not applicable