RX400h · Service Manual BODY ELECTRICAL

Speaker Circuit

Circuit diagnosis

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.
As for the vehicle with a navigation system, the sound signal on the driver's side is sent to the navigation ECU from the stereo component amplifier.
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 speaker.
Standard System:
There are two cases when a short is detected.
  1. When a short is detected in the front No.1 speaker circuit, sound cannot be heard only from the front No.1 speaker.
  2. When a short is detected in any circuit other than the front No.1 speaker circuit, sound cannot be heard from all speakers including the front No.1 speaker.
Mark Levinson System:
When a short is detected in the speaker circuit, sound cannot be heard from all speakers.

WIRING DIAGRAM

E110900E02
E110932E01

INSPECTION PROCEDURE

NOTICE:
If the vehicle is equipped with the navigation system, proceed to the flow chart "Driver Side Speaker Circuit" for troubleshooting of the front stereo component speaker and front No.2 speaker on the driver side (Click here).


1. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER - SPEAKER)

  1. I046059E02
    Disconnect the connectors shown in the illustration from the stereo component amplifier and speakers.

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

    Standard resistance:
    Below 1 Ω

  1. Measure the resistance between each of the front No.2 speakers (except the center speaker) and the front stereo component speaker to check for an open circuit in the wire harness.

    Standard resistance:
    Below 1 Ω

  1. Measure the resistance between each of the front stereo component speakers and the stereo component amplifier to check for an open circuit in the wire harness.

    Standard resistance:
    Below 1 Ω

  1. Mark Levinson System:Measure the resistance between the front No.2 speaker (center speaker) and the stereo component amplifier to check for an open circuit in the wire harness.

    Standard resistance:
    Below 1 Ω

  1. 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

  1. 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



 NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2. INSPECT FRONT NO.1 SPEAKER

  1. Resistance check.

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

      NOTICE:
      The speakers should not be removed for checking.

      Standard resistance:
      Standard system:
      Approximately 2 Ω
      Mark Levinson system:
      Approximately 7 to 9 Ω



 NG
REPLACE FRONT NO.1 SPEAKER
OK


3. INSPECT FRONT NO.2 SPEAKER

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

    Standard:
    Malfunction disappears.

    HINT:
    1. Connect all the connectors to the speakers.
    2. 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.



 OK
REPLACE FRONT NO.2 SPEAKER
NG


4. INSPECT FRONT STEREO COMPONENT SPEAKER

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

    Standard:
    Malfunction disappears.

    HINT:
    1. Connect all the connectors to the speakers.
    2. When there is a possibility that either the right or left front speaker is defective, inspect by interchanging the right one with the left one.



 OK
REPLACE FRONT STEREO COMPONENT SPEAKER
NG


5. INSPECT REAR SPEAKER

  1. Resistance check.

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

      NOTICE:
      The speakers should not be removed for checking.

      Standard resistance:
      Standard system:
      Approximately 4 Ω
      Mark Levinson system:
      Approximately 14 to 18 Ω



 NG
REPLACE REAR SPEAKER
OK

RETURN TO THE ORIGINAL INSPECTION FLOW BECAUSE THE CHECK RESULT IS NORMAL


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