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 REAR MOUNT CAMERA CONDITION Is the rear mount camera lens soiled by dust or dirt?	Yes	Clean the rear mount camera lens, then go to Step 8.
1		No	Go to the next step.
2	VERIFY IF MALFUNCTION CAUSE IS REAR MOUNT CAMERA Are there any scratches or damage on the rear mount camera lens?	Yes	Replace the rear mount camera lens, then go to Step 8. (See REAR MOUNT CAMERA REMOVAL/INSTALLATION .)
2		No	Go to the next step.
3	INSPECT REAR MOUNT CAMERA CONNECTOR Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Disconnect the rear mount camera 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.
3		No	Repair or replace the connector, then go to Step 8.
4	INSPECT CMU CONNECTOR Disconnect the CMU 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.
4		No	Repair or replace the connector, then go to Step 8.
5	VERIFY IF MALFUNCTION CAUSE IS OPEN CIRCUIT IN WIRING HARNESS BETWEEN CMU AND REAR MOUNT CAMERA Verify that the rear mount camera and CMU connectors are disconnected. Inspect the wiring harness for continuity between the following terminals (vehicle wiring harness side). CMU terminal 1B and rear mount camera terminal D CMU terminal 1C and rear mount camera terminal F CMU terminal 1D and rear mount camera terminal C Is there continuity?	Yes	Go to the next step.
5		No	Refer to the wiring diagram and verify if there is a common connector between the following terminals. CMU terminal 1B and rear mount camera terminal D CMU terminal 1C and rear mount camera terminal F CMU terminal 1D and rear mount camera terminal C If there is a common connector: Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for an open circuit to determine the malfunctioning location. Repair or replace the malfunctioning location. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to Step 8.
6	VERIFY IF MALFUNCTION CAUSE IS SHORT CIRCUIT TO POWER SUPPLY IN WIRING HARNESS BETWEEN CMU AND REAR MOUNT CAMERA Verify that the rear mount camera and CMU connectors are disconnected. Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Switch the ignition to ACC or ON (engine off or on). Measure the voltage at the following terminals (vehicle wiring harness side). Rear mount camera terminal D Rear mount camera terminal F Rear mount camera terminal C Is the voltage B+ ?	Yes	Refer to the wiring diagram and verify if there is a common connector between the following terminals. CMU terminal 1B and rear mount camera terminal D CMU terminal 1C and rear mount camera terminal F CMU terminal 1D and rear mount camera terminal C If there is a common connector: Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location. Repair or replace the malfunctioning location. If there is no common connector: Repair or replace the wiring harness which is shorted to the power supply. Go to Step 8.
6		No	Go to the next step.
7	DETERMINE IF MALFUNCTION CAUSE IS REAR MOUNT CAMERA Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Replace the rear mount camera. (See REAR MOUNT CAMERA REMOVAL/INSTALLATION .) Connect all the connectors. Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Apply the parking brake. Switch the ignition to ACC or ON (engine off or on). Shift to the R position. Is rear mount camera image output normally?	Yes	Troubleshooting completed (explain the contents of the servicing to the customer).
7		No	Replace the CMU, then go to the next step. (See CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION .)
8	VERIFY IF MALFUNCTION CAUSE IS CORRECTED Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Connect all the connectors. Reconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Apply the parking brake. Switch the ignition to ACC or ON (engine off or on). Shift to the R position. Is rear mount camera image output normally?	Yes	Troubleshooting completed (explain the contents of the servicing to the customer).
8		No	Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis. (See SYMPTOM TROUBLESHOOTING [ENTERTAINMENT SYSTEM [WITH CENTER DISPLAY]] .)