No.2 CALLER'S VOICE VOLUME TOO LOW, OR NOISE INTERRUPTS CALL [HANDS-FREE TELEPHONE (HF/TEL) SYSTEM]

id0903h4844100

2 | Caller’s voice volume too low, or noise interrupts call
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Possible DTC | 26:Er81, 26:Er82, 26:Er83, 26:Er84, 26:Er86
Possible cause | • Malfunction in the microphone related parts ― Open or short circuit in the wiring harness between the microphone and the HF/TEL unit ― Microphone malfunction ― Poor connection in the connector • Malfunction in the audio control switch ― Voice recognition/hands-free switch malfunction ― Open or short circuit in the wiring harness between the voice recognition/hands-free switch and the audio unit ― Poor connection in the connector • HF/TEL unit does not receive the vehicle speed signal ― CAN communication error • Malfunction in the audio system ― Audio control switch and/or related circuit malfunction • Influence due to vehicle driving conditions ― Noise while driving is loud (engine, tire noise, blower fan noise) ― Windows and/or Convertible top/Power retractable hardtop are open • HF/TEL unit malfunction • Problem in the cellular phone ― Vehicle is in a place where signal transmission is weak ― Bluetooth does not operate

Diagnostic procedure

• When performing an asterisked (*) troubleshooting inspection, slightly shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunction. If there is a problem, verify that the connectors, terminals and wiring harness are connected correctly and undamaged.

STEP | INSPECTION | ACTION
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1* | • Can the audio volume be controlled using audio control switch? | Yes | Go to the next step.
No | Inspect and repair the audio control switch and related wiring harness.
2 | • Does the symptom appear under following conditions? ― Windows and/or Convertible top/Power retractable hardtop are open ― Noise while driving is loud (engine, tire noise, blower fan noise) | Yes | The system is normal. (Influence due to vehicle driving conditions)
No | Go to the next step.
3 | • Perform the audio system on-board diagnostic. • Is 26:Er81 displayed? | Yes | Inspect and repair the audio system CAN communication.
No | Go to the next step.
4* | • Inspect for open or short circuits in the following wiring harnesses and connectors, and inspect the connector connections. ― Between microphone terminal A and HF/TEL unit terminal B ― Between microphone terminal B and HF/TEL unit terminal D ― Between microphone terminal C and HF/TEL unit terminal U ― Between microphone terminal D and GND ― Between microphone terminal E and HF/TEL unit terminal J • Are the harnesses and connector connections normal? | Yes | Go to the next step.
No | Repair or replace malfunctioning parts.
5 | • Inspect the following switches. (See AUDIO CONTROL SWITCH INSPECTION.) ― Voice recognition/hands-free switch • Are the switches normal? | Yes | Go to the next step.
No | Replace the audio control switch. (See AUDIO CONTROL SWITCH REMOVAL/INSTALLATION.)
6* | • Inspect for open or short circuits in the following wiring harnesses and connectors, and inspect the connector connections. ― Between audio unit (24-pin) terminal 1N and audio control switch terminal G • Are the harnesses and connector connections normal? | Yes | Go to the next step.
No | Repair or replace malfunctioning parts.
7 | • Make a call with the cellular phone without using HF/TEL system. • Does the same symptom appear? | Yes | Cellular phone related problem.
No | Go to the next step.
8 | • Call the hands-free cell phone using another cellular phone. • Does the same symptom appear? | Yes | Go to the next step.
No | The cellular phone Bluetooth system is malfunctioning.
9 | • Replace the microphone. (See MICROPHONE REMOVAL/INSTALLATION.) • Does the same symptom appear? | Yes | Replace the HF/TEL unit. (See HANDS-FREE TELEPHONE (HF/TEL) UNIT REMOVAL/INSTALLATION.)
No | Troubleshooting is completed. (Microphone malfunction)