Toyota Sienna Service Manual: Noise Occurs

INSPECTION PROCEDURE

1 NOISE CONDITION

1. Check in which direction the noise comes from (front left or right, or rear left or right).

1.  Check in which direction the noise comes from.

OK: The location of the noise source can be determined

2 CHECK SPEAKERS

1. Check the installation conditions of the speaker units that are located near the noise source and that there are no cracks, scratches, deformation, or other failures.

Result

3 CHECK NOISE CONDITIONS

1. Check the noise condition.

HINT: The radio has a noise prevention function to reduce noise when listening to the radio. If a loud noise occurs, check whether the ground at the antenna mounting base and the noise prevention unit are installed and wired correctly.

HINT:

•  In the chart's left column, find the situation that matches the customer's complaint. Then, in the right column, find the part that is causing the noise. Check the noise filter on or for the part.
•  To save time and avoid a misdiagnosis, first make sure that the noise is not coming from outside the vehicle.
•  Noise should be removed in descending order of loudness.
•  Setting the radio to a frequency where no signal is received may make recognition of the noise problem easier.

OK: The noise source can not be determined.

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE