DTC U0422:00 [RADAR UNIT]

id1502a6019600

System malfunction location	Error signal received from front body control module (FBCM)
Detection condition	•  Communication error between front body control module (FBCM) and radar unit
Fail-safe	•  Inhibits the Mazda radar cruise control (MRCC) system control •  Inhibits the smart brake support (SBS) system control
Possible cause	•  Front body control module (FBCM) malfunction •  Radar unit malfunction
System wiring diagram	•  Not applicable

Diagnostic Procedure

Step	Inspection		Action
1	PERFORM DTC INSPECTION FOR FRONT BODY CONTROL MODULE (FBCM) •  Perform the front body control module (FBCM) DTC inspection using the M-MDS. (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].) •  Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].) Then go to Step 3.
		No	Go to the next step.
2	PERFORM DTC INSPECTION FOR RADAR UNIT •  Clear radar unit DTCs using the M-MDS. (See CLEARING DTC [RADAR UNIT].) •  Switch the ignition ON (engine on). •  Perform the radar unit DTC inspection using the M-MDS. (See DTC INSPECTION [RADAR UNIT].) •  Is the same DTC present?	Yes	Replace the front body control module (FBCM), then go to the next step. (See FRONT BODY CONTROL MODULE (FBCM) REMOVAL/INSTALLATION.)
		No	Go to the next step.
3	VERIFY THAT REPAIRS HAVE BEEN COMPLETED •  Clear radar unit DTCs using the M-MDS. (See CLEARING DTC [RADAR UNIT].) •  Switch the ignition ON (engine on). •  Perform the radar unit DTC inspection using the M-MDS. (See DTC INSPECTION [RADAR UNIT].) •  Is the same DTC present?	Yes	Repeat the inspection from Step 1. •  If the malfunction does not recur, go to the next step. •  If the malfunction recurs, replace the radar unit. (See RADAR UNIT REMOVAL/INSTALLATION.) Go to the next step.
		No	Go to the next step.
4	VERIFY THAT NO OTHER DTCs ARE PRESENT •  Verify other DTCs displayed. •  Are any other DTCs output?	Yes	Perform the corresponding DTC inspection.
		No	DTC troubleshooting completed.