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
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

STEP	INSPECTION		ACTION
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)