Diagnostic Procedure

DTC U0423:68 (VEHICLE CONTROL MODULE) DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	INSPECT VEHICLE CONTROL MODULE (VCM) AND BODY CONTROL MODULE (BCM) FOR MALFUNCTION Perform the DTC inspection for the vehicle control module (VCM) and the body control module (BCM). (See DTC INSPECTION .) Is a DTC related to an internal malfunction displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [VEHICLE CONTROL MODULE (US)] .) (See DTC TABLE [BODY CONTROL MODULE (BCM) (US)] .)
1		No	Go to the next step.
2	INSPECT INSTRUMENT CLUSTER FOR MALFUNCTION Perform the DTC inspection for the instrument cluster. (See DTC INSPECTION .) Is a DTC displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [BODY CONTROL MODULE (BCM) (US)] .)
2		No	Go to the next step.
3	CLOCK SPRING CONNECTOR FOR MALFUNCTION Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION .) Are the connector and terminal normal?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning location and perform the repair completion verification.
4	CRUISE CONTROL SWITCH CIRCUIT FOR SHORT TO GROUND Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification.
5	CRUISE CONTROL SWITCH FOR MALFUNCTION Inspect the applicable part. (See CRUISE CONTROL SWITCH INSPECTION [MAZDA RADAR CRUISE CONTROL (MRCC) SYSTEM] .) Is the part normal?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See CRUISE CONTROL SWITCH REMOVAL/INSTALLATION [MAZDA RADAR CRUISE CONTROL (MRCC) SYSTEM] .)
6	INSPECT INSTRUMENT CLUSTER CONNECTOR FOR MALFUNCTION Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION .) Are the connector and terminal normal?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning location and perform the repair completion verification.
7	INSPECT INSTRUMENT CLUSTER FOR MALFUNCTION DEPENDING ON REPEATABILITY Install/connect the part removed/disconnected during the troubleshooting procedure. Clear the DTC recorded in the memory. (See CLEARING DTC .) Perform the DTC inspection for the vehicle control module (VCM). (See DTC INSPECTION .) Is the same Pending DTC present?	Yes	Refer to the CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(US)] .) If the CAN communication is normal, replace the instrument cluster and perform the repair completion verification. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION .)
7		No	Perform the [ACTION FOR NON-REPEATABLE MALFUNCTIONS]. (See TROUBLESHOOTING PROCEDURE [(US)] .) If DTC is displayed Repeat the diagnosis from Step 1. If DTC is not displayed Go to repair completion verification 2.
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED Install/connect the part removed/disconnected during the troubleshooting procedure. Clear the DTC recorded in the memory. (See CLEARING DTC .) Perform the DTC inspection for the vehicle control module (VCM). (See DTC INSPECTION .) Is the same Pending DTC present?	Yes	Refer to the CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(US)] .) If the CAN communication is normal, perform the diagnosis from Step 1. If the malfunction recurs, replace the body control module (BCM), then go to the next step. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION .)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	VERIFY IF OTHER DTC IS DISPLAYED Perform the DTC inspection. (See DTC INSPECTION .) Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.