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DTC U0121:00 [VEHICLE CONTROL MODULE (E)]

id1502c50344cb

Without Mazda M Hybrid

Outline

System malfunction location

Communication error with DSC HU/CM

Detection condition

•  The vehicle control module (VCM) cannot receive CAN signal from DSC HU/CM for 10 s.

Fail-safe

(See DTC TABLE [VEHICLE CONTROL MODULE (E)].)

Possible cause

•  Malfunction in CAN communication line between vehicle control module (VCM) and DSC HU/CM

•  DSC HU/CM malfunction

•  Vehicle control module (VCM) malfunction (built into body control module (BCM))

System wiring diagram

Not applicable

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

Diagnostic Procedure

• Perform an inspection in accordance with the multiplex communication system diagnostic procedure. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)

With Mazda M Hybrid

Outline

System malfunction location

Communication error with electronically controlled brake unit

Detection condition

•  The vehicle control module (VCM) cannot receive CAN signal from electronically controlled brake unit for 10 s.

Fail-safe

(See DTC TABLE [VEHICLE CONTROL MODULE (E)].)

Possible cause

•  Malfunction in CAN communication line between vehicle control module (VCM) and electronically controlled brake unit

•  Electronically controlled brake unit malfunction

•  Vehicle control module (VCM) malfunction (built into body control module (BCM))

System wiring diagram

Not applicable

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

Diagnostic Procedure

• Perform an inspection in accordance with the multiplex communication system diagnostic procedure. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)