Diagnostic Procedure

WARNING: This page is about a different car, the 2016 Mazda CX-5. However, it is still accessible from the selected car via links, so may be relevant.

Step	Inspection		Action
1	INSPECT BLIND SPOT MONITORING (BSM) CONTROL MODULE (LH) Switch the ignition to off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Disconnect the blind spot monitoring (BSM) control module (LH) connector. Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. Is the connector normal?	Yes	Go to the next step.
1		No	Repair or replace the connector, then go to Step 7.
2	INSPECT BLIND SPOT MONITORING (BSM) CONTROL MODULE (RH) CONNECTOR Disconnect the blind spot monitoring (BSM) control module (RH) connector. Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. Is the connector normal?	Yes	Go to the next step.
2		No	Repair or replace the connector, then go to Step 7.
3	INSPECT FOR SHORT TO GROUND IN CAN COMMUNICATION CIRCUIT BETWEEN BLIND SPOT MONITORING (BSM) CONTROL MODULE (LH) AND (RH) Verify that the blind spot monitoring (BSM) control module (LH) and (RH) connectors are disconnected. Inspect for continuity between the following terminals (wiring harness-side) and body ground: Blind spot monitoring (BSM) control module (LH) terminal A Blind spot monitoring (BSM) control module (LH) terminal B Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: Blind spot monitoring (BSM) control module (LH) terminal A-Blind spot monitoring (BSM) control module (RH) terminal A Blind spot monitoring (BSM) control module (LH) terminal B-Blind spot monitoring (BSM) control module (RH) terminal B If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. Go to Step 7.
3		No	Go to the next step.
4	INSPECT FOR SHORT TO POWER SUPPLY IN CAN COMMUNICATION CIRCUIT BETWEEN BLIND SPOT MONITORING (BSM) CONTROL MODULE (LH) AND (RH) Verify that the blind spot monitoring (BSM) control module (LH) and (RH) connectors are disconnected. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Switch the ignition ON (engine off or on). Measure the voltage at the following terminals (wiring harness-side): Blind spot monitoring (BSM) control module (LH) terminal A Blind spot monitoring (BSM) control module (LH) terminal B Is the voltage 0 V ?	Yes	Go to the next step.
4		No	Refer to the wiring diagram and verify whether or not there is a common connector between following terminals: Blind spot monitoring (BSM) control module (LH) terminal A-Blind spot monitoring (BSM) control module (RH) terminal A Blind spot monitoring (BSM) control module (LH) terminal B-Blind spot monitoring (BSM) control module (RH) terminal B If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to power supply. Go to Step 7.
5	INSPECT FOR OPEN CIRCUIT IN CAN COMMUNICATION CIRCUIT BETWEEN BLIND SPOT MONITORING (BSM) CONTROL MODULE (LH) AND (RH) Switch the ignition to off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Verify that the blind spot monitoring (BSM) control module (LH) and (RH) connectors are disconnected. Inspect for continuity between the following terminals (wiring harness-side): Blind spot monitoring (BSM) control module (LH) terminal A-Blind spot monitoring (BSM) control module (RH) terminal A Blind spot monitoring (BSM) control module (LH) terminal B-Blind spot monitoring (BSM) control module (RH) terminal B Is there continuity?	Yes	NOTE: Keep the replaced blind spot monitoring (BSM) control module (LH) because it may be used for diagnosis later. Replace the blind spot monitoring (BSM) control module (LH).(See BLIND SPOT MONITORING (BSM) CONTROL MODULE REMOVAL/INSTALLATION .)Go to the next step.
5		No	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: Blind spot monitoring (BSM) control module (LH) terminal A-Blind spot monitoring (BSM) control module (RH) terminal A Blind spot monitoring (BSM) control module (LH) terminal B-Blind spot monitoring (BSM) control module (RH) terminal B If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to step 7.
6	PERFORM DTC INSPECTION AND VERIFY BLIND SPOT MONITORING (BSM) CONTROL MODULE (LH) MALFUNCTION Always reconnect all disconnected connectors. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Clear the DTC for the blind spot monitoring (BSM) control module (RH) using the M-MDS. (See CLEARING DTC [BLIND SPOT MONITORING (BSM) SYSTEM] .) Switch the ignition ON (engine off or on) and wait for 1 s or more. Retrieve the blind spot monitoring (BSM) control module (RH) DTCs using the M-MDS. (See DTC TABLE [BLIND SPOT MONITORING (BSM) SYSTEM] .) Is the same DTC displayed?	Yes	Remove the blind spot monitoring (BSM) control module (RH) and install the blind spot monitoring (BSM) control module (LH) replaced in Step 5. (See BLIND SPOT MONITORING (BSM) CONTROL MODULE REMOVAL/INSTALLATION .) Go to the next step.
6		No	Go to Step 8.
7	VERIFY THAT REPAIRS HAVE BEEN COMPLETED Always reconnect all disconnected connectors. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Clear the DTC for the blind spot monitoring (BSM) control module (RH) using the M-MDS. (See CLEARING DTC [BLIND SPOT MONITORING (BSM) SYSTEM] .) Switch the ignition ON (engine off or on) and wait for 1 s or more. Retrieve the blind spot monitoring (BSM) control module (RH) DTCs using the M-MDS. (See DTC TABLE [BLIND SPOT MONITORING (BSM) SYSTEM] .) Is the same DTC displayed?	Yes	Repeat the diagnosis from Step 1.
7		No	Go to the next step.
8	VERIFY IF OTHER DTCs DISPLAYED Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [BLIND SPOT MONITORING (BSM) SYSTEM] .)
8		No	DTC troubleshooting completed.