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Symptom Troubleshooting (Audio): NVH Mazda 6 GH

NO. 1 AF NOISE OR POP NOISE ON ALL SOURCES (RADIO, CD, CASSETTE TAPE)

1AF noise or POP noise on all sources (Radio, CD, Cassette tape)/Possible DTC: 09:Er20, 09:Er21
Troubleshooting hints Low vehicle battery voltage. Jammed radio signals from after market equipment. Speaker malfunction (e.g., any foreign material, broken) Improper speaker installation Audio unit malfunction Audio amplifier malfunction (with BOSE) Poor connection of audio unit connector, terminal damage Antenna malfunction (e.g., poor ground) Open or short circuit in wiring harness between audio amplifier and ground (with BOSE) Woofer malfunction (with BOSE) Poor connection of woofer connector, terminal damage (with BOSE) NOTE: AF noise is "Petit Petit" noise that generally occurs with switch ON/OFF operations of electrical equipment other than the audio unit, or "Gee" continual noise that occurs when electrical equipment is operated. This is caused by noise entrance to the power supply wiring, signal wiring, speaker cable or head of cassette deck etc. Therefore noise can be heard regardless of radio wave condition or audio volume position. The noise will start after one click from the minimum position of volume button but normally does not change even when volume is turned to higher position. POP noise is "Putsun", "Poco" or "Putsun" noise that occurs with switch ON/OFF operation of the audio unit, or with switching Radio to CD. Even normal audio unit sometimes emit small noise depending on conditions.
NOTE
AF noise is "Petit Petit" noise that generally occurs with switch ON/OFF operations of electrical equipment other than the audio unit, or "Gee" continual noise that occurs when electrical equipment is operated. This is caused by noise entrance to the power supply wiring, signal wiring, speaker cable or head of cassette deck etc. Therefore noise can be heard regardless of radio wave condition or audio volume position. The noise will start after one click from the minimum position of volume button but normally does not change even when volume is turned to higher position. POP noise is "Putsun", "Poco" or "Putsun" noise that occurs with switch ON/OFF operation of the audio unit, or with switching Radio to CD. Even normal audio unit sometimes emit small noise depending on conditions.

TROUBLESHOOTING HINTS - AF NOISE OR POP NOISE ON ALL SOURCES (RADIO, CD, CASSETTE TAPE)

STEPINSPECTIONACTION
1Inspect the vehicle battery voltage. Is the vehicle battery voltage normal? Specification: Ignition switch ON: 11.5 V or more Idle: 12.5 V or moreYesGo to the next step.
NoCharge the battery, then go to the next step.
2Turn the audio system on. Is there any noise?YesGo to the next step.
NoThe system is normal. Explain to the customer that the vehicle battery voltage was low.
3Is any of the following aftermarket equipment installed? (Inspect especially near the antenna). Radar Remote engine starter Anti-theft device OtherYesGo to the next step.
NoGo to the Step 5.
4Remove the aftermarket equipment. Turn the audio system on. Is there any noise?YesGo to the next step.
NoThe system is normal. The aftermarket electrical devices might make a noise.
5Is there the noise from all speakers?YesGo to the Step 7.
NoGo to the next step.
6Inspect the suspect speaker. Is the speaker normal?YesGo to the next step.
NoIf there is any foreign material on the speaker: Remove the foreign material from the speaker. If the speaker is malfunctioning: Replace the speaker. (See FRONT DOOR SPEAKER REMOVAL/INSTALLATION. ) (See REAR DOOR SPEAKER REMOVAL/INSTALLATION. ) (See WOOFER REMOVAL/INSTALLATION [SPORT SEDAN]. ) (See WOOFER REMOVAL/INSTALLATION [5-DOOR, SPORT WAGON]. ) (See TWEETER REMOVAL/INSTALLATION. ) If the speaker is not installed properly: Install the speaker properly.
7Attempt to duplicate the symptom on the other vehicle. Is the noise better than the customer's vehicle?YesGo to the next step, (with BOSE) Go to Step 11. (without BOSE)
NoThe system is normal. Explain the noise generation mechanism to the customer. NOTE: The noise may be heard depends on the operating speed of audio power and/or mode switch.
8Is there any noise from the woofer?YesGo to the next step.
NoGo to Step 11.
9Turn the ignition switch to the LOCK position. Remove the woofer. Inspect the connection of the woofer connector (6-pin) terminal A (B+), B (GND), G (WOOF IN+) and H (WOOF IN-). Is the connector connected securely?YesReplace the woofer. (See WOOFER REMOVAL/INSTALLATION [SPORT SEDAN]. ) (See WOOFER REMOVAL/INSTALLATION [5-DOOR, SPORT WAGON]. )
NoRepair or replace the terminal or connector. Go to the next step.
10Is there any noise?YesReplace the woofer. (See WOOFER REMOVAL/INSTALLATION [SPORT SEDAN]. ) (See WOOFER REMOVAL/INSTALLATION [5-DOOR, SPORT WAGON]. )
NoThe system is normal.
11Turn the ignition switch to the LOCK position. Remove the audio unit. Inspect the connection of the audio unit connector (24-pin) (for sound signal line). Is the connector connected securely?YesGo to Step 13. (with BOSE) Go to Step 14. (without BOSE)
NoRepair or replace the terminal or connector. Go to the next step.
12Is there any noise?YesGo to the next step, (with BOSE) Go to Step 14. (without BOSE)
NoThe system is normal.
13Turn the ignition switch to the LOCK position. Disconnect the audio amplifier connector. Inspect between the audio amplifier wiring harness-side connector (26-pin) terminal V and ground. Is there continuity?YesGo to Step 15.
NoRepair or replace the terminal or connector. Go to the next step.
14Is there any noise?YesGo to the next step.
NoThe system is normal.
15Inspect the ground condition of the manual antenna. Is the ground condition normal?YesReplace the audio amplifier. (See AUDIO AMPLIFIER REMOVAL/INSTALLATION. )
NoRepair or replace the ground: Go to the next step.
16Is there any noise?YesReplace the audio amplifier. (See AUDIO AMPLIFIER REMOVAL/INSTALLATION. )
NoThe system is normal.
NOTE
The noise may be heard depends on the operating speed of audio power and/or mode switch.

DIAGNOSTIC PROCEDURE

NO. 2 NOISE FROM RADIO (AM ONLY)

2Noise from radio (AM only)/Possible DTC: 09:Er22
POSSIBLE CAUSEAntenna rod not installed Jamming from aftermarket electronic equipment (two-way radio, navigation system, mobile phone, etc.] Noise from electrical system on vehicle (e.g. fuel pump) Battery malfunction Charging system malfunction Audio unit malfunction Antenna plug poor connection Antenna feeder malfunction Electronic jamming from outside, or inferior condition of broadcasting station radio wave Antenna installation loosened

POSSIBLE CAUSE (NOISE FROM RADIO - AM ONLY)

STEPINSPECTIONACTION
1Tune to local broadcasting station and check reception condition. Is reception okay?YesTune to correct frequency of broadcasting station. If not preset, preset it.
NoGo to the next step.
2Inspect antenna rod condition. Is antenna rod installed?YesGo to the next step.
NoAdvise customer to install antenna rod when radio is used.
3Is aftermarket electronic equipment (two-way radio, navigation system, mobile phone, etc). installed? NOTE: TV antenna located closely to audio antenna can be cause of noise. Relocate TV antenna.YesGo to the next step.
NoGo to Step 5.
4Remove aftermarket electronic equipment. Turn audio unit on and check reception condition. Is reception improved?YesThe system is normal. (Explain to customers that aftermarket electronic equipment is cause of noise)
NoGo to the next step.
5Measure battery voltage. Is battery voltage okay? Standard With ignition switch ON: 11.5 V or more At idling: 12.5 V or more NOTE: Inspect that battery cables are connected to terminals securely.YesGo to the next step.
NoCharge battery. Inspect charging system, and repair or replace if necessary.
6Is noise occurring only when vehicle electrical system (e.g. fuel pump) operates? NOTE: Identify subject electrical component by disconnecting fuse, turning switch ON & OFF, or disconnecting & connecting connector. It will be easy when simulation function on M-MDS is used.YesGo to the next step.
NoGo to Step 8.
7Inspect power supply, ground condition, and noise prevention capacitor for electrical component. Is noise present after inspection? NOTE: Inspect following: Power supply to electrical component for voltage drop (compare with battery voltage) Resistance between ground of electrical component and body. (Should be close to 0 ohm) Installation condition of noise prevention capacitor for fuel pump etc.YesGo to the next step.
NoTroubleshooting completed. NOTE: The audio unit supplies 12 V battery power to the antenna amplifier for the AM radio reception in the radio mode. The audio unit cannot receive the AM signals without the 12 V battery power to the antenna amplifier. If the AM signals become strong, the audio unit may receive the signal with noises.
8Inspect antenna plug connection condition. Is connection okay?YesGo to the next step.
NoInsert antenna plug securely.
9Turn the ignition switch to the LOCK position. Measure continuity between antenna feeder axis and ground. Is there any continuity?YesReplace antenna feeder. (See ANTENNA FEEDER LOCATION [SPORT SEDAN]. ) (See ANTENNA FEEDER LOCATION [5-DOOR]. ) (See ANTENNA FEEDER LOCATION [SPORT WAGON]. )
NoGo to the next step.
10Compare reception with other audio unit on same model (model/unit) under same problem conditions. Is reception equivalent between customer's unit and compared unit? NOTE: Due to following differences, you may feel difference in reception efficiency. (Vehicle side factor) Antenna installation location, height, feeder wiring routing, optional electrical equipment (Audio unit factor) Volume concern type: It decreases change of volume when signals become weak. (Noise is easy to be conspicuous) Noise decrease type: It decreases volume when signals become weak, so that noise is not conspicuous.YesThe system is normal (It is caused by electronic jamming from outside, or inferior broadcasting station signal condition).
NoGo to the next step.
11Retighten ground for antenna and antenna amplifier. Retighten antenna rod. Is noise present, after retightening?YesReplace audio unit. (See CENTER PANEL UNIT REMOVAL/INSTALLATION. ) (See CENTER PANEL UNIT DISASSEMBLY/ASSEMBLY. ) (See AUDIO UNIT DISASSEMBLY/ASSEMBLY. )
NoTroubleshooting completed.
NOTE
TV antenna located closely to audio antenna can be cause of noise. Relocate TV antenna.
NOTE
Inspect that battery cables are connected to terminals securely.
NOTE
Identify subject electrical component by disconnecting fuse, turning switch ON & OFF, or disconnecting & connecting connector. It will be easy when simulation function on M-MDS is used.
NOTE
Inspect following: Power supply to electrical component for voltage drop (compare with battery voltage) Resistance between ground of electrical component and body. (Should be close to 0 ohm) Installation condition of noise prevention capacitor for fuel pump etc.
NOTE
The audio unit supplies 12 V battery power to the antenna amplifier for the AM radio reception in the radio mode. The audio unit cannot receive the AM signals without the 12 V battery power to the antenna amplifier. If the AM signals become strong, the audio unit may receive the signal with noises.
NOTE
Due to following differences, you may feel difference in reception efficiency. (Vehicle side factor) Antenna installation location, height, feeder wiring routing, optional electrical equipment (Audio unit factor) Volume concern type: It decreases change of volume when signals become weak. (Noise is easy to be conspicuous) Noise decrease type: It decreases volume when signals become weak, so that noise is not conspicuous.

DIAGNOSTIC PROCEDURE

NO. 3 NOISE FROM RADIO (FM ONLY)

3Noise from radio (FM only)/Possible DTC: 09:Er22
POSSIBLE CAUSEAntenna rod not installed Jamming from aftermarket electronic equipment (two-way radio, navigation system, mobile phone, etc). Noise from electrical system on vehicle (e.g. fuel pump) Battery malfunction Charging system malfunction Audio unit malfunction Antenna plug poor connection Antenna feeder malfunction Electronic jamming from outside, or inferior condition of broadcasting station radio wave Antenna installation loosened NOTE: FM broadcast has feature "sound quality is good" and "resistant to noise", but FM broadcast has particular noises. Though audio unit is designed to reduce noise, there are times noise occurs due to conditions.
NOTE
FM broadcast has feature "sound quality is good" and "resistant to noise", but FM broadcast has particular noises. Though audio unit is designed to reduce noise, there are times noise occurs due to conditions.

POSSIBLE CAUSE (NOISE FROM RADIO - FM ONLY)

STEPINSPECTIONACTION
1Tune to local broadcasting station and check reception condition. Is reception okay?YesTune to correct frequency of broadcasting station. If not preset, preset it.
NoGo to the next step.
2Inspect antenna rod condition. Is antenna rod installed?YesGo to the next step.
NoAdvise customer to install antenna rod when radio is used.
3Is aftermarket electronic equipment (two-way radio, navigation system, mobile phone, etc). installed?YesGo to the next step.
NoGo to Step 5.
4Remove aftermarket electronic equipment. Turn audio unit ON and check reception condition. Is reception improved?YesThe system is normal. (Explain to customers that aftermarket electronic equipment is cause of noise)
NoGo to the next step.
5Measure battery voltage. Is battery voltage okay? Standard With ignition switch ON: 11.5 V or more At idling: 12.5 V or more NOTE: Inspect that battery cables are connected to terminals securely.YesGo to the next step.
NoCharge battery. Inspect charging system, and repair or replace if necessary.
6Is noise occurring only when vehicle electrical system (e.g. fuel pump) operates? NOTE: Identify subject electrical component by disconnecting fuse, turning switch ON & OFF, or disconnecting & connecting connector. It will be easy when simulation function on M-MDS is used.YesGo to the next step.
NoGo to Step 8.
7Inspect power supply, ground condition, and noise prevention capacitor for electrical component. Is noise present after inspection? NOTE: Inspect following: Power supply to electrical component for voltage drop (compare with battery voltage) Resistance between ground of electrical component and body. (Should be close to 0 ohm) Installation condition of noise prevention capacitor for fuel pump etc.YesGo to the next step.
NoTroubleshooting completed.
8Inspect antenna plug connection condition. Is connection okay?YesGo to the next step.
NoInsert antenna plug securely.
9Turn ignition switch to LOCK position. Measure continuity between antenna feeder axis and ground. Is there any continuity?YesReplace antenna feeder. (See ANTENNA FEEDER LOCATION [SPORT SEDAN]. ) (See ANTENNA FEEDER LOCATION [5-DOOR]. ) (See ANTENNA FEEDER LOCATION [SPORT WAGON]. )
NoGo to the next step.
10Compare reception with other audio unit on same model (model/unit) under same problem conditions. Is reception equivalent between customer's unit and compared unit?YesThe system is normal (It is caused by electronic jamming from outside, or inferior broadcasting station signal condition).
NoGo to the next step.
11Retighten ground fixation for antenna installation part and antenna amplifier. Retighten antenna rod. Is noise present, after retightening? NOTE: When antenna is not grounded properly, FM noise is likely to be noticed.YesReplace audio unit. (See CENTER PANEL UNIT REMOVAL/INSTALLATION. ) (See CENTER PANEL UNIT DISASSEMBLY/ASSEMBLY. ) (See AUDIO UNIT DISASSEMBLY/ASSEMBLY. )
NoTroubleshooting completed.
NOTE
Inspect that battery cables are connected to terminals securely.
NOTE
Identify subject electrical component by disconnecting fuse, turning switch ON & OFF, or disconnecting & connecting connector. It will be easy when simulation function on M-MDS is used.
NOTE
Inspect following: Power supply to electrical component for voltage drop (compare with battery voltage) Resistance between ground of electrical component and body. (Should be close to 0 ohm) Installation condition of noise prevention capacitor for fuel pump etc.
NOTE
When antenna is not grounded properly, FM noise is likely to be noticed.

DIAGNOSTIC PROCEDURE