Toyota Sienna Service Manual: Speaker Circuit

DESCRIPTION

•  When the vehicle has a built-in type amplifier, a sound signal is sent from the radio receiver to the speakers via the "6 Speaker System" circuit.
•  When the vehicle has a separate type amplifier, a sound signal from the radio receiver is amplified by the stereo component amplifier and then transmitted to the speaker via the "10 Speaker System" 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

WIRING DIAGRAM

1 CHECK HARNESS AND CONNECTOR

1. Disconnect the connectors shown in the illustration from the stereo component amplifier or radio receiver and speakers.
2.  10 Speaker System: Measure the resistance between each of 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.  6 speaker System: Measure the resistance between each of the front No. 2 speakers and the radio receiver to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

4.  Measure the resistance between each of the front No. 2 speakers and each of the front No. 1 speakers to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

5.  10 Speaker System: Measure the resistance between each of the rear speakers and the stereo component amplifier to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

6.  6 Speaker System: Measure the resistance between each of the rear speakers and the radio receiver to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

7.  10 Speaker System: Measure the resistance between each of the rear stereo component speakers and the stereo component amplifier to check for an open circuit in the wire harness.

   Standard resistance: Below 1 Ω

8.  10 Speaker System: 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

9. 10 Speaker System: 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

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

    Standard resistance: 10 kΩ or higher

2 INSPECT FRONT NO. 1 SPEAKER

1. Resistance check.

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

   Standard resistance: 10 Speaker System: 4 to 6 Ω
   6 Speaker System: Approximately 4 Ω

3 INSPECT REAR SPEAKER

1. Resistance check.

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

   10 Speaker System: Approximately 2.4 Ω
   6 Speaker System: Approximately 4 Ω

4 INSPECT FRONT NO. 2 SPEAKER

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

   Standard: Malfunction disappears.

HINT:

•  Connect all the connectors to the front No. 2 speaker.
• When there is a possibility that either the right or left front speaker is detective, inspect by interchanging the right one with the left one.
•  Perform the above inspection on both LH and RH sides.

5 CONFIRM MODEL

Result

6 INSPECT WOOFER BOX SPEAKER

1. Resistance check.

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

NOTICE: The speaker should not be removed for checking.

Standard resistance

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 speaker.
•  When there is a possibility that either the right or left rear speaker is detective, inspect by interchanging the right one with the left one

8 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

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE