Toyota Sienna Service Manual: Speaker Circuit

DESCRIPTION

The sound signal that has been amplified by the stereo component amplifier is sent to the speakers from the stereo component amplifier through this circuit.

If there is a short in this circuit, the stereo component amplifier detects it and stops output to the speakers.

Thus sound cannot be heard from the speakers even if there is no malfunction in the stereo component amplifier or speakers.

When a short is detected in the speaker circuit, no sound can be heard from the speakers.

WIRING DIAGRAM

INSPECTION PROCEDURE

1 CHECK HARNESS AND CONNECTOR

1. Disconnect the connectors shown in the illustration on the left from the stereo component amplifier and speakers.
2.  Measure the resistance between the front No. 2 speakers and the stereo component amplifier to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

3.  Measure the resistance between rear speakers and the stereo component amplifier to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

4.  Measure the resistance between the front stereo component speaker and the stereo component amplifier to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

5.  Measure the resistance between the woofer box speaker and the stereo component amplifier to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

6.  Measure the resistance between the front No. 1 speaker and the front No. 2 speaker to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

7.  Measure the resistance between the rear stereo component speaker and the stereo component amplifier to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

8.  Measure the resistance between each speaker and body ground to check for a short circuit in the wire harness.

   Standard resistance: 10 kΩ or higher

2 INSPECT WOOFER BOX SPEAKER

1. Resistance check.
2.  Measure the resistance according to the value(s) in the table below.

NOTICE: The speaker should not be removed for checking.

Standard resistance

INSPECT FRONT NO. 1 SPEAKER

1. Resistance check.

1. Measure the resistance between the terminals of the speaker.

Standard resistance: 4 to 6 Ω

4 INSPECT FRONT NO. 2 SPEAKER

1. Check that the malfunction disappears when another speaker in good condition is installed.

OK: Malfunction disappears.

HINT:

•  Connect all the connectors to the front No. 2 speakers.
•  When there is a possibility that either right or left front speaker is defective, inspect by interchanging the right one with the left one.

5 INSPECT REAR SPEAKER

1. Resistance check.

1.  Measure the resistance between the terminals of the speaker.

Standard resistance: Approximately 2.6 Ω

6 INSPECT FRONT STEREO COMPONENT SPEAKER

1. Resistance check.

1.  Measure the resistance between the terminals of the speaker.

Standard resistance: 1.2 to 2.2 Ω

7 INSPECT REAR STEREO COMPONENT SPEAKER

1. Check that the malfunction disappears when another speaker in good condition is installed.

OK: Malfunction disappears.

HINT:

•  Connect all the connectors to the rear stereo component speakers.
•  When there is a possibility that either right or left front speaker is defective, inspect by interchanging the right one with the left one.

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE