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 B1238:49 (CONNECTIVITY MASTER UNIT) DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	INSPECT AUDIO AMPLIFIER FOR MALFUNCTION Clear the DTC recorded in the memory. (Refer to the [CLEARING DTC] in the appropriate service information) Perform the DTC inspection for the connectivity master unit (CMU). (Refer to the [DTC INSPECTION] in the appropriate service information) Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (Refer to the [CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW] in the appropriate service information) If the CAN communication is normal, replace the audio amplifier and perform the repair completion verification. (Refer to the [AUDIO AMPLIFIER REMOVAL/INSTALLATION] in the appropriate service information)
1		No	Go to the next step.
Repair completion verification	VERIFY IF OTHER DTCs ARE DISPLAYED Perform the DTC inspection. (Refer to the [DTC INSPECTION] in the appropriate service information) Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification		No	DTC troubleshooting completed.