Diagnostic Procedure

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

NO SOUND OUTPUT IN ALL MODES (ENTERTAINMENT SYSTEM - WITH CENTER DISPLAY) - DIAGNOSTIC PROCEDURE

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 NO SOUND OUTPUT IN MULTIPLE MODES [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 10.
2	INSPECT TAU CONNECTOR 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 13.
3	INSPECT AUDIO AMPLIFIER CONNECTOR Disconnect the audio amplifier 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 13.
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 13.
5	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 the next step.
5		No	Inspect the AUDIO2 7.5A fuse. If the fuse is blown: Refer to the wiring diagram and verify if there is a common connector between AUDIO2 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 ACC relay 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 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 13.
6	VERIFY IF MALFUNCTION CAUSE IS OPEN CIRCUIT IN WIRING HARNESS BETWEEN TAU AND BODY GROUND Verify that the TAU connector is disconnected. Inspect the wiring harness for continuity between the following terminals (vehicle wiring harness side). TAU terminal 2W and body ground Is there continuity?	Yes	Go to the next step.
6		No	Refer to the wiring diagram and verify if there is a common connector between the following terminals. TAU terminal 2W and body ground 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 13.
7	VERIFY IF MALFUNCTION CAUSE IS OPEN CIRCUIT IN WIRING HARNESS BETWEEN AUDIO AMPLIFIER AND BODY GROUND Verify that the audio amplifier connectors are disconnected. Inspect the wiring harness for continuity between the following terminals (vehicle wiring harness side). Audio amplifier terminal 2J and body ground Audio amplifier terminal 3B and body ground Is there continuity?	Yes	Go to the next step.
7		No	Refer to the wiring diagram and verify if there is a common connector between the following terminals. Audio amplifier terminal 2J and body ground Audio amplifier terminal 3B and body ground 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 13.
8	DETERMINE IF MALFUNCTION CAUSE IS AUDIO AMPLIFIER Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Replace the audio amplifier. (See AUDIO AMPLIFIER 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	Go to Step 13.
8		No	Go to the next step.
9	DETERMINE IF MALFUNCTION CAUSE IS TAU 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	Go to Step 13.
9		No	Replace the CMU, then go to Step 13. (See CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION .)
10	INSPECT SPEAKERS 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 FRONT SIDE SPEAKER INSPECTION .) (See FRONT CENTER SPEAKER INSPECTION .) (See REAR SPEAKER INSPECTION .) Is the speaker resistance normal?	Yes	Go to the next step.
10		No	Replace the malfunctioning speaker, then go to Step 13. (See FRONT DOOR SPEAKER REMOVAL/INSTALLATION .) (See REAR DOOR SPEAKER REMOVAL/INSTALLATION .) (See FRONT SIDE SPEAKER REMOVAL/INSTALLATION .) (See FRONT CENTER SPEAKER REMOVAL/INSTALLATION .) (See REAR SPEAKER REMOVAL/INSTALLATION .)
11	INSPECT SPEAKER CIRCUIT FOR OPEN CIRCUIT Disconnect the connector of the malfunctioning speaker and the audio amplifier connector. Verify the continuity of the wiring harness between the following terminals (vehicle wiring harness side) of the speakers which are malfunctioning. Audio amplifier terminal 3C and front door speaker (LH) terminal C Audio amplifier terminal 3D and front door speaker (LH) terminal B Audio amplifier terminal 3E and front door speaker (RH) terminal C Audio amplifier terminal 3F and front door speaker (RH) terminal B Audio amplifier terminal 3G and rear door speaker (LH) terminal B Audio amplifier terminal 3H and rear door speaker (LH) terminal C Audio amplifier terminal 2A and rear door speaker (RH) terminal C Audio amplifier terminal 2B and rear door speaker (RH) terminal B Audio amplifier terminal 2C and front side speaker (LH) terminal A Audio amplifier terminal 2E and front side speaker (LH) terminal B Audio amplifier terminal 2K and front side speaker (RH) terminal A Audio amplifier terminal 2M and front side speaker (RH) terminal B Audio amplifier terminal 2G and front center speaker terminal B Audio amplifier terminal 2I and front center speaker terminal A Audio amplifier terminal 2O and rear speaker (LH) terminal B Audio amplifier terminal 2P and rear speaker (LH) terminal A Audio amplifier terminal 2O and rear speaker (RH) terminal B Audio amplifier terminal 2P and rear speaker (RH) terminal A Is there continuity?	Yes	Go to the next step.
11		No	Refer to the wiring diagram and verify if there is a common connector between the following terminals. Audio amplifier terminal 3C and front door speaker (LH) terminal C Audio amplifier terminal 3D and front door speaker (LH) terminal B Audio amplifier terminal 3E and front door speaker (RH) terminal C Audio amplifier terminal 3F and front door speaker (RH) terminal B Audio amplifier terminal 3G and rear door speaker (LH) terminal B Audio amplifier terminal 3H and rear door speaker (LH) terminal C Audio amplifier terminal 2A and rear door speaker (RH) terminal C Audio amplifier terminal 2B and rear door speaker (RH) terminal B Audio amplifier terminal 2C and front side speaker (LH) terminal A Audio amplifier terminal 2E and front side speaker (LH) terminal B Audio amplifier terminal 2K and front side speaker (RH) terminal A Audio amplifier terminal 2M and front side speaker (RH) terminal B Audio amplifier terminal 2G and front center speaker terminal B Audio amplifier terminal 2I and front center speaker terminal A Audio amplifier terminal 2O and rear speaker (LH) terminal B Audio amplifier terminal 2P and rear speaker (LH) terminal A Audio amplifier terminal 2O and rear speaker (RH) terminal B Audio amplifier terminal 2P and rear speaker (RH) terminal A 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 13.
12	INSPECT SPEAKER CIRCUIT FOR SHORT TO GROUND Verify that the connector of the malfunctioning speaker and the audio amplifier connector are disconnected. Inspect for continuity between the following terminals (vehicle wiring harness side) of the speakers which are malfunctioning and body ground. Front door speaker (LH) terminal C Front door speaker (LH) terminal B Front door speaker (RH) terminal C Front door speaker (RH) terminal B Rear door speaker (LH) terminal B Rear door speaker (LH) terminal C Rear door speaker (RH) terminal C Rear door speaker (RH) terminal B Front side speaker (LH) terminal A Front side speaker (LH) terminal B Front side speaker (RH) terminal A Front side speaker (RH) terminal B Front center speaker terminal B Front center speaker terminal A Rear speaker (LH) terminal B Rear speaker (LH) terminal A Rear speaker (RH) terminal B Rear speaker (RH) terminal A Is there continuity?	Yes	Refer to the wiring diagram and verify if there is a common connector between the following terminals. Audio amplifier terminal 3C and front door speaker (LH) terminal C Audio amplifier terminal 3D and front door speaker (LH) terminal B Audio amplifier terminal 3E and front door speaker (RH) terminal C Audio amplifier terminal 3F and front door speaker (RH) terminal B Audio amplifier terminal 3G and rear door speaker (LH) terminal B Audio amplifier terminal 3H and rear door speaker (LH) terminal C Audio amplifier terminal 2A and rear door speaker (RH) terminal C Audio amplifier terminal 2B and rear door speaker (RH) terminal B Audio amplifier terminal 2C and front side speaker (LH) terminal A Audio amplifier terminal 2E and front side speaker (LH) terminal B Audio amplifier terminal 2K and front side speaker (RH) terminal A Audio amplifier terminal 2M and front side speaker (RH) terminal B Audio amplifier terminal 2G and front center speaker terminal B Audio amplifier terminal 2I and front center speaker terminal A Audio amplifier terminal 2O and rear speaker (LH) terminal B Audio amplifier terminal 2P and rear speaker (LH) terminal A Audio amplifier terminal 2O and rear speaker (RH) terminal B Audio amplifier terminal 2P and rear speaker (RH) terminal A 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. Go to the next step.
12		No	Go to the next step.
13	VERIFY IF MALFUNCTION CAUSE IS CORRECTED 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).
13		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]] .)

NO SOUND OUTPUT IN ALL MODES (ENTERTAINMENT SYSTEM - WITH CENTER DISPLAY) - DIAGNOSTIC PROCEDURE

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 NO SOUND OUTPUT IN MULTIPLE MODES [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 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 9.
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 the next step.
4		No	Inspect the AUDIO2 7.5A fuse. If the fuse is blown: Refer to the wiring diagram and verify if there is a common connector between AUDIO2 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 ACC relay 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 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 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	Go to Step 9.
6		No	Replace the CMU, then go to Step 9. (See CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION .)
7	INSPECT SPEAKERS 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 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]] .)