Diagnostic Procedure

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

DTC U0428:00 OR U0428:83 (ELECTRIC POWER STEERING (EPS)) DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	VERIFY BODY CONTROL MODULE (BCM) DTC Using the M-MDS, perform the body control module (BCM) DTC inspection. (See DTC INSPECTION .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [BODY CONTROL MODULE (BCM) (US)] .) DTC troubleshooting completed, then perform the repair completion verification.
1		No	Go to the next step.
Repair completion verification	VERIFY DTC TROUBLESHOOTING COMPLETED Using the M-MDS, clear the DTC from the EPS control module. (See CLEARING DTC .) Using the M-MDS, perform the EPS control module DTC inspection. (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). (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION (US) .)
Repair completion verification		No	DTC troubleshooting completed.