DTC U0401:00 [VEHICLE CONTROL MODULE (V/C-MODULE)]

id0102i0851700

System malfunction location	Error signal received from PCM
Detection condition	•  Communication error between PCM and vehicle control module (V/C-module)
Fail-safe	•  Inhibits the mazda radar cruise control (MRCC) system control
Possible cause	•  PCM malfunction (engine speed signal malfunction) •  Vehicle control module (V/C-module) malfunction
System wiring diagram	•  Not applicable

Diagnostic Procedure

Step	Inspection		Action
1	PERFORM DTC INSPECTION FOR PCM •  Perform the PCM DTC inspection using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-D 2.2].) •  Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See DTC TABLE [SKYACTIV-D 2.2].) Then go to Step 3.
		No	Go to the next step.
2	PERFORM DTC INSPECTION FOR VEHICLE CONTROL MODULE (V/C-MODULE) •  Clear vehicle control module (V/C-module) DTCs using the M-MDS. (See CLEARING DTC [VEHICLE CONTROL MODULE (V/C-MODULE)].) •  Switch the ignition ON (engine on). •  Perform the vehicle control module (V/C-module) DTC inspection using the M-MDS. (See DTC INSPECTION [VEHICLE CONTROL MODULE (V/C-MODULE)].) •  Is the same DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
		No	Go to the next step.
3	VERIFY THAT REPAIRS HAVE BEEN COMPLETED •  Clear vehicle control module (V/C-module) DTCs using the M-MDS. (See CLEARING DTC [VEHICLE CONTROL MODULE (V/C-MODULE)].) •  Switch the ignition ON (engine on). •  Perform the vehicle control module (V/C-module) DTC inspection using the M-MDS. (See DTC INSPECTION [VEHICLE CONTROL MODULE (V/C-MODULE)].) •  Is the same DTC present?	Yes	Repeat the inspection from Step 1. •  If the malfunction recurs, replace the vehicle control module (V/C-module). (See VEHICLE CONTROL MODULE (V/C-MODULE) REMOVAL/INSTALLATION [MAZDA RADAR CRUISE CONTROL (MRCC) SYSTEM].) 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.