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	VERIFY MALFUNCTION SYMPTOM Switch the ignition to ACC or ON (engine off or on). Launch the on-board diagnostic assist function. (See DIAGNOSTIC ASSIST FUNCTION [CONNECTIVITY MASTER UNIT] .) Select assist code "94". Press the [ENTER] and verify that the sound is output from each speaker. Is sound output from each speaker in the order?	Yes	System is normal. Due to the possibility that sound is not output in some modes, verify the malfunction in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis. (See SYMPTOM TROUBLESHOOTING [ENTERTAINMENT SYSTEM [WITH CENTER DISPLAY]] .)
1		No	No sound is produced from all speakers Go to the next step. No sound is produced from some speakers Go to Step 7.
2	INSPECT TAU 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 TAU 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 10.
3	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.
3		No	Repair or replace the connector, then go to Step 9.
4	INSPECT TAU ACC POWER SUPPLY VOLTAGE Verify that the TAU connector is 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 TAU terminal 2R (vehicle wiring harness side). Is the voltage B+ ?	Yes	Go to Step 6.
4		No	Inspect the AUDIO 7.5A fuse. If the fuse is blown: Refer to the wiring diagram and verify if there is a common connector between AUDIO 7.5A fuse and the TAU terminal 2R. 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 ground 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 ground. Replace the fuse. If the fuse is damaged: Replace the fuse. If the fuse is normal: Refer to the wiring diagram and verify if there is a common connector between battery and TAU terminal 2R. 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 9.
5	INSPECT WIRING HARNESS BETWEEN TAU AND BODY GROUND FOR OPEN CIRCUIT Verify that the TAU connector is disconnected. Inspect for continuity between the following terminals (vehicle wiring harness side) and body ground. TAU terminal 2W 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 and body ground. TAU terminal 2W 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. Repair or replace the malfunctioning location. Repair or replace the wiring harness which has an open circuit. Go to Step 9.
6	DETERMINE IF MALFUNCTION CAUSE IS TAU 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 TAU. (See TUNER AND AMP UNIT (TAU) 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] .) Switch the ignition to ACC or ON (engine off or on). Launch the on-board diagnostic assist function. (See DIAGNOSTIC ASSIST FUNCTION [CONNECTIVITY MASTER UNIT] .) Select assist code "94". Press the [ENTER] and verify that the sound is output from each speaker. Is sound output from each speaker in the order?	Yes	Troubleshooting completed (explain the contents of the servicing to the customer).
6		No	Replace the CMU, then go to Step 9. (See CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION .)
7	INSPECT SPEAKERS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Inspect the malfunctioning speaker. (See FRONT DOOR SPEAKER INSPECTION .) (See REAR DOOR SPEAKER INSPECTION .) (See TWEETER INSPECTION .) Is the speaker resistance normal?	Yes	Go to the next step.
7		No	Replace the malfunctioning speaker, then go to Step 9. (See FRONT DOOR SPEAKER REMOVAL/INSTALLATION .) (See REAR DOOR SPEAKER REMOVAL/INSTALLATION .) (See TWEETER REMOVAL/INSTALLATION .)
8	INSPECT SPEAKER CIRCUIT FOR OPEN CIRCUIT Disconnect the connector of the malfunctioning speaker and the TAU connector. Verify the continuity of the wiring harness between the following terminals (vehicle wiring harness side) of the speakers which are malfunctioning. TAU terminal 2A and front door speaker (LH) terminal C TAU terminal 2C and front door speaker (LH) terminal B TAU terminal 2A and tweeter (LH) terminal B TAU terminal 2C and tweeter (LH) terminal A TAU terminal 2D and front door speaker (RH) terminal C TAU terminal 2F and front door speaker (RH) terminal B TAU terminal 2D and tweeter (RH) terminal B TAU terminal 2F and tweeter (RH) terminal A TAU terminal 2S and rear door speaker (LH) terminal C TAU terminal 2U and rear door speaker (LH) terminal B TAU terminal 2V and rear door speaker (RH) terminal C TAU terminal 2X and rear door speaker (RH) terminal B Is there continuity?	Yes	Go to the next step.
8		No	Refer to the wiring diagram and verify if there is a common connector between the following terminals. TAU terminal 2A and front door speaker (LH) terminal C TAU terminal 2C and front door speaker (LH) terminal B TAU terminal 2A and tweeter (LH) terminal B TAU terminal 2C and tweeter (LH) terminal A TAU terminal 2D and front door speaker (RH) terminal C TAU terminal 2F and front door speaker (RH) terminal B TAU terminal 2D and tweeter (RH) terminal B TAU terminal 2F and tweeter (RH) terminal A TAU terminal 2S and rear door speaker (LH) terminal C TAU terminal 2U and rear door speaker (LH) terminal B TAU terminal 2V and rear door speaker (RH) terminal C TAU terminal 2X and rear door speaker (RH) terminal B 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 the next step.
9	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] .) Switch the ignition to ACC or ON (engine off or on). Launch the on-board diagnostic assist function. (See DIAGNOSTIC ASSIST FUNCTION [CONNECTIVITY MASTER UNIT] .) Select assist code "94". Press the [ENTER] and verify that the sound is output from each speaker. Is sound output from each speaker in the order?	Yes	Troubleshooting completed (explain the contents of the servicing to the customer).
9		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]] .)