Home

Mazdamanuals.com

DTC U0121:87 [BODY CONTROL MODULE (BCM) (E)]

id0902r70960s3

Without Mazda M Hybrid

Outline

System malfunction location

Communication error with DSC HU/CM

Detection condition

• The body control module (BCM) cannot receive CAN signal from the DSC HU/CM.

Fail-safe

Not applicable

Possible cause

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

System wiring diagram

Not applicable

System malfunction location	Communication error with DSC HU/CM
Detection condition	• The body control module (BCM) cannot receive CAN signal from the DSC HU/CM.
Fail-safe	Not applicable
Possible cause	• Malfunction in CAN communication line between DSC HU/CM and 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 body control module (BCM) cannot receive CAN signal from the electronically controlled brake unit.

Fail-safe

Not applicable

Possible cause

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

System wiring diagram

Not applicable

System malfunction location	Communication error with electronically controlled brake unit
Detection condition	• The body control module (BCM) cannot receive CAN signal from the electronically controlled brake unit.
Fail-safe	Not applicable
Possible cause	• Malfunction in CAN communication line between electronically controlled brake unit and 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)].)