Possible DTC

Volume increases/decreases while driving the vehicle

Possible cause

• Electronic jamming from outside, or inferior condition of broadcasting station radio wave

• Sound level difference between audio modes

• Mis-operation of steering switches

• Audio unit malfunction (without Bose^®)

• Audio amplifier malfunction (with Bose^®)

NOTE:

• Inspect the ALC function (without Bose^®)/AudioPilot^®2 function (with Bose^®) while driving the vehicle with playing the CD, etc.

STEP

INSPECTION

ACTION

1

• Does the audio volume change only while in radio mode?

Yes

Go to the next step.

No

Go to Step 3.

2

• Can the location where the audio volume change be specified?

Yes

The system is normal. Explain to the customer that the noise is caused by radio wave disturbances or broadcast wave conditions from the outside.

No

Go to Step 5.

3

• Does the audio volume change when changing the mode?

Yes

The system is normal. Explain to the customer that the volume change is caused by sound level differences between audio modes.

No

Go to the next step.

4

• Do the steering switches operate?

Yes

The system is normal. Explain to the customer that the volume change is caused by a mis-operation of the steering switches.

No

Go to the next step.

5

• Does the ALC (Without Bose^®)/AudioPilot^®2 function (With Bose^®) turn on?

Yes

Go to the next step.

No

Without Bose®:

• Replace the audio unit.

  (See AUDIO UNIT REMOVAL/INSTALLATION.)

With Bose®:

• Replace the audio amplifier.

  (See AUDIO AMPLIFIER REMOVAL/INSTALLATION.)

6

• Turn off the ALC (Without Bose^®)/AudioPilot^®2 function (With Bose^®).

• Does the sound change while driving the vehicle?

Yes

Replace the audio unit.

(See AUDIO UNIT REMOVAL/INSTALLATION.)

No

The system is normal.

Explains the ALC (Without Bose^®)/AudioPilot^®2 function (with Bose^®) to the customer.