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

id0903h5844100

2	Caller’s voice volume too low, or noise interrupts call
Possible DTC	With M-MDS	B1134:23, B116A:12, B116A:13, B116A:16, B116A:44, U0498:68
	Without M-MDS	Audio unit •  26:Er81, 82, 83, 84, 85, 86 Car-navigation unit •  Device code 26/Error code 81, 82, 83, 84, 85, 86
POSSIBLECAUSE	•  Malfunction in the microphone related parts ―  Open or short circuit in the wiring harness between the microphone and the Bluetooth unit ―  Microphone malfunction ―  Poor connection in the connector •  Malfunction in the Voice switch (with audio system) ―  HF/TEL switch malfunction ―  Open or short circuit in the wiring harness between the HF/TEL switch and the audio unit car-navigation unit ―  Poor connection in the connector •  Malfunction in the HF/TEL switch (with car-navigation system) ―  HF/TEL switch malfunction ―  Open or short circuit in the wiring harness between the HF/TEL switch and the audio unit car-navigation unit ―  Poor connection in the connector •  Malfunction in the audio system ―  Steering 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 sunroof are open •  Bluetooth unit malfunction •  Problem in the cellular phone ―  Vehicle is in a place where signal transmission is weak ―  Bluetooth does not operate ―  A cellular phone other than a Hands-free telephone system-enabled models is used.

Diagnostic procedure

STEP	INSPECTION		ACTION
1*	•  Can the audio volume be controlled using steering switch?	Yes	Go to the next step.
		No	Inspect and repair the steering switch and related wiring harness.
2	•  Does the symptom appear under following conditions? ―  Windows and/or sunroof 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 Bluetooth system on-board diagnostic. •  Is U0498:68, 26:Er81, device code 26/error code 81displayed?	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 Bluetooth unit terminal A ―  Between microphone terminal B and Bluetooth unit terminal B ―  Between microphone terminal C and Bluetooth unit terminal C ―  Between microphone terminal E (L.H.D.)/F (R.H.D.) and Bluetooth unit terminal E •  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 STEERING SWITCH INSPECTION.) ―  HF/TEL switch •  Are the switches normal?	Yes	Go to the next step.
		No	Replace the steering switch. (See STEERING SWITCH REMOVAL/INSTALLATION.)
6*	•  Inspect for open or short circuits in the following wiring harnesses and connectors, and inspect the connector connections. ―  Between Bluetooth unit (28-pin) terminal F and steering switch terminal L •  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 Bluetooth unit 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 Bluetooth unit. (See Bluetooth UNIT REMOVAL/INSTALLATION.)
		No	Troubleshooting is completed. (The microphone is malfunctioning.)