Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HARNESS AND CONNECTOR
1. Disconnect the connectors from the stereo component amplifier and speakers.
2. 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
3. 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
4. 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
5. with Front Center Speaker:
  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
6. Measure the resistance between each of the rear speakers and the stereo component amplifier to check for an open circuit in the wire harness.
  
  Fig 1: Identifying Stereo Component Amplifier Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Standard resistance:
  
  Below 1 Ω
7. Measure the resistance between each speaker and body ground to check for a short circuit in the wire harness.
  
  Fig 2: Identifying Speaker Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Standard resistance:
  
  10 kΩ or higher
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next step
INSPECT FRONT NO. 1 SPEAKER
1. Resistance check
  1. Measure the resistance between the terminals of the speaker.
    Standard resistance:
    
    with Front Center Speaker:
    
    7 to 9 Ω
    
    without Front Center Speaker:
    
    Approximately 2 Ω
    
    HINT:
    
    Perform the above inspection on both LH and RH sides.
NG: REPLACE FRONT NO. 1 SPEAKER

OK: Go to Next step
INSPECT FRONT NO. 2 SPEAKER
1. Resistance check
  1. Measure the resistance between the terminals of the speaker.
    Standard resistance:
    
    with Front Center Speaker:
    
    7 to 9 Ω
    
    without Front Center Speaker:
    
    Approximately 4 Ω
    
    HINT:
    
    Perform the above inspection on both LH and RH sides.
NG: REPLACE FRONT NO. 2 SPEAKER

OK: Go to Next step
INSPECT FRONT STEREO COMPONENT 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 stereo component speakers.
  - 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.
  - Perform the above inspection on both LH and RH sides.
OK: REPLACE FRONT STEREO COMPONENT SPEAKER

NG: Go to Next step
INSPECT REAR SPEAKER
1. Resistance check
  1. Measure the resistance between the terminals of the speakers.
    Standard resistance:
    
    with Front Center Speaker:
    
    14 to 18 Ω
    
    without Front Center Speaker:
    
    Approximately 4 Ω
    
    HINT:
    
    Perform the above inspection on both LH and RH sides.
NG: REPLACE REAR SPEAKER

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE