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 B11BA:13 (CONNECTIVITY MASTER UNIT) DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	DETERMINE IF MALFUNCTION IS STEERING SWITCH Switch the ignition ON (engine off or on). Display the [Steering SW Inspection] using the diagnostic assist function. (See DIAGNOSTIC ASSIST FUNCTION [CONNECTIVITY MASTER UNIT (US)] .) Among the following switches, are there any that match the operation results display when the steering switch is operated? Audio system switches (VOL-, VOL+, SEEK-, SEEK+, MUTE) Hands-free system switches (SOURCE, PICK-UP/VOICE, HANG-UP)	Yes	Both audio system switches and hands-free system switches match: Verify that the repairs have been completed. Only audio system switches match: Go to Step 7. Only hands-free system switches match: Go to the next step.
1		No	Go to Step 12.
2	VERIFY CLOCK SPRING (AUDIO SYSTEM) VOLTAGE Switch the ignition ON (engine off). Measure the voltage at clock spring terminal 3J. Is the voltage between 2.68-2.89 V?	Yes	Go to the next step.
2		No	Voltage exceeds 2.89 V: Go to Step 4. Voltage is less than 2.68 V: Go to Step 5.
3	INSPECT STEERING SWITCH FOR MALFUNCTION Inspect the applicable part. (Refer to the [STEERING SWITCH INSPECTION] in the appropriate service information) Is the part normal?	Yes	Verify that the repairs have been completed.
3		No	Repair or replace the malfunctioning location and perform the repair completion verification. (Refer to the [STEERING SWITCH REMOVAL/INSTALLATION] in the appropriate service information)
4	INSPECT STEERING SWITCH SIGNAL CIRCUIT (AUDIO) FOR SHORT TO POWER SUPPLY Inspect the applicable circuit for a short to power supply. (Refer to the [CIRCUIT INSPECTION] in the appropriate service information) Is the circuit normal?	Yes	Verify that the repairs have been completed.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification.
5	INSPECT STEERING SWITCH SIGNAL CIRCUIT (AUDIO) FOR SHORT TO GROUND Inspect the applicable circuit for a short to ground. (Refer to the [CIRCUIT INSPECTION] in the appropriate service information) Is the circuit normal?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning location and perform the repair completion verification.
6	INSPECT STEERING SWITCH SIGNAL CIRCUIT (AUDIO) FOR OPEN CIRCUIT Inspect the applicable circuit for an open circuit. (Refer to the [CIRCUIT INSPECTION] in the appropriate service information) Is the circuit normal?	Yes	Verify that the repairs have been completed.
6		No	Repair or replace the malfunctioning location and perform the repair completion verification.
7	VERIFY CLOCK SPRING (HANDS-FREE SYSTEM) VOLTAGE Switch the ignition ON (engine off). Measure the voltage at clock spring terminal 3L. Is the voltage between 2.520-2.736 V?	Yes	Go to the next step.
7		No	Voltage exceeds 2.736 V: Go to Step 9. Voltage is less than 2.520 V: Go to Step 10.
8	INSPECT STEERING SWITCH FOR MALFUNCTION Inspect the applicable part. (Refer to the [STEERING SWITCH INSPECTION] in the appropriate service information) Is the part normal?	Yes	Verify that the repairs have been completed.
8		No	Repair or replace the malfunctioning location and perform the repair completion verification. (Refer to the [STEERING SWITCH REMOVAL/INSTALLATION] in the appropriate service information)
9	INSPECT STEERING SWITCH SIGNAL CIRCUIT (HANDS-FREE) FOR SHORT TO POWER SUPPLY Inspect the applicable circuit for a short to power supply. (Refer to the [CIRCUIT INSPECTION] in the appropriate service information) Is the circuit normal?	Yes	Verify that the repairs have been completed.
9		No	Repair or replace the malfunctioning location and perform the repair completion verification.
10	INSPECT STEERING SWITCH SIGNAL CIRCUIT (HANDS-FREE) FOR SHORT TO GROUND Inspect the applicable circuit for a short to ground. (Refer to the [CIRCUIT INSPECTION] in the appropriate service information) Is the circuit normal?	Yes	Go to the next step.
10		No	Repair or replace the malfunctioning location and perform the repair completion verification.
11	INSPECT STEERING SWITCH SIGNAL CIRCUIT (HANDS-FREE) FOR OPEN CIRCUIT Inspect the applicable circuit for an open circuit. (Refer to the [CIRCUIT INSPECTION] in the appropriate service information) Is the circuit normal?	Yes	Verify that the repairs have been completed.
11		No	Repair or replace the malfunctioning location and perform the repair completion verification.
12	VERIFY CLOCK SPRING (AUDIO, HANDS-FREE, AND GROUND SYSTEMS) VOLTAGE Switch the ignition ON (engine off). Measure the voltage at the following terminals. Clock spring terminal 3J Clock spring terminal 3D Clock spring terminal 3L Are the voltage values as follows? Clock spring terminal 3J: 2.68-2.89 V Clock spring terminal 3D: 0 V Clock spring terminal 3L: 2.520-2.736 V	Yes	Go to the next step.
12		No	Go to Step 15.
13	INSPECT CLOCK SPRING (3A-3N TERMINAL) CONNECTOR FOR MALFUNCTION Inspect the applicable connector and terminal. (Refer to the [CONNECTOR INSPECTION] in the appropriate service information) Are the connector and terminal normal?	Yes	Go to the next step.
13		No	Repair or replace the malfunctioning location and perform the repair completion verification.
14	INSPECT STEERING SWITCH FOR MALFUNCTION Inspect the applicable part. (Refer to the [STEERING SWITCH INSPECTION] in the appropriate service information) Is the part normal?	Yes	Verify that the repairs have been completed.
14		No	Repair or replace the malfunctioning location and perform the repair completion verification. (Refer to the [STEERING SWITCH REMOVAL/INSTALLATION] in the appropriate service information)
15	VERIFY CONNECTIVITY MASTER UNIT (CMU) (AUDIO, HANDS-FREE, AND GROUND SYSTEMS) VOLTAGE Switch the ignition ON (engine off). Measure the voltage at the following terminals. Connectivity master unit (CMU) terminal 1N Connectivity master unit (CMU) terminal 1L Connectivity master unit (CMU) terminal 1J Are the voltage values as follows? Connectivity master unit (CMU) terminal 1N: 2.68-2.89 V Connectivity master unit (CMU) terminal 1L: 0 V Connectivity master unit (CMU) terminal 1J: 2.520-2.736 V	Yes	Go to the next step.
15		No	Replace the connectivity master unit (CMU) and perform the repair completion verification. (Refer to the [CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION] in the appropriate service information)
16	INSPECT CONNECTIVITY MASTER UNIT (CMU) CONNECTOR FOR MALFUNCTION Inspect the applicable connector and terminal. (Refer to the [CONNECTOR INSPECTION] in the appropriate service information) Are the connector and terminal normal?	Yes	Go to the next step.
16		No	Repair or replace the malfunctioning location and perform the repair completion verification.
17	INSPECT CLOCK SPRING (TERMINAL 1A-1N) CONNECTOR FOR MALFUNCTION Inspect the applicable connector and terminal. (Refer to the [CONNECTOR INSPECTION] in the appropriate service information) Are the connector and terminal normal?	Yes	Go to the next step.
17		No	Repair or replace the malfunctioning location and perform the repair completion verification.
18	INSPECT STEERING SWITCH SIGNAL CIRCUIT (AUDIO), SIGNAL CIRCUIT (HANDS-FREE), AND GROUND CIRCUIT FOR SHORT TO POWER SUPPLY Inspect the applicable circuit for a short to power supply. (Refer to the [CIRCUIT INSPECTION] in the appropriate service information) Is the circuit normal?	Yes	Go to the next step.
18		No	Repair or replace the malfunctioning location and perform the repair completion verification.
19	INSPECT STEERING SWITCH SIGNAL CIRCUIT (AUDIO), SIGNAL CIRCUIT (HANDS-FREE), AND GROUND CIRCUITS FOR SHORT TO GROUND Inspect the applicable circuit for a short to ground. (Refer to the [CIRCUIT INSPECTION] in the appropriate service information) Is the circuit normal?	Yes	Go to the next step.
19		No	Repair or replace the malfunctioning location and perform the repair completion verification.
20	INSPECT STEERING SWITCH SIGNAL CIRCUITS (AUDIO), SIGNAL CIRCUITS (HANDS-FREE), AND GROUND CIRCUITS FOR SHORT CIRCUIT Inspect the applicable circuits for a short circuit. (Refer to the [CIRCUIT INSPECTION] in the appropriate service information) Is the circuit normal?	Yes	Go to the next step.
20		No	Repair or replace the malfunctioning location and perform the repair completion verification.
21	INSPECT CLOCK SPRING FOR MALFUNCTION Inspect the applicable part. (Refer to the [CLOCK SPRING INSPECTION] in the appropriate service information) Is the part normal?	Yes	Go to the next step.
21		No	Repair or replace the malfunctioning location and perform the repair completion verification. (Refer to the [CLOCK SPRING REMOVAL/INSTALLATION] in the appropriate service information)
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. (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, perform the diagnosis from Step 1. If the malfunction recurs, replace the connectivity master unit (CMU), then go to the next step. (Refer to the [CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION] in the appropriate service information)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	VERIFY IF OTHER DTCs ARE DISPLAYED Perform the DTC inspection. (Refer to the [DTC INSPECTION] in the appropriate service information) Are other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.