Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT TELEPHONE SWITCH ASSY
1. Disconnect the O6 switch connector.
2. Measure the resistance between the terminals of the switch connector when each switch is pressed.
  Standard:
  
  Fig 1: Tester Specification
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 2: Disconnecting O6 Switch Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE TELEPHONE SWITCH ASSY (See MAYDAY SYSTEM )

OK: Go to next step.
CHECK WIRE HARNESS (TELEPHONE TRANSCEIVER ASSY - TELEPHONE ECU ASSY)
1. Disconnect the A ECU and G transceiver connectors.
2. Measure the resistance between the wire harness side connectors.
  Standard:
  
  Fig 3: Tester Specification
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 4: Disconnecting A ECU And G Transceiver Connectors
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step
CHECK WIRE HARNESS (TELEPHONE ECU ASSY - TELEPHONE SWITCH ASSY, TELEPHONE SWITCH ASSY - BODY GROUND)
1. Disconnect the A ECU and O6 switch connectors.
2. Measure the resistance between the wire harness side connectors.
  Standard:
  
  Fig 5: Tester Specification
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 6: Disconnecting A ECU And O6 Switch Connectors
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step
CHECK WIRE HARNESS (REAR SPEAKER ASSY (REAR DOOR LH) - TELEPHONE ECU ASSY)
1. Disconnect the A ECU and R16 speaker connectors.
2. Measure the resistance between the wire harness side connectors.
  Standard:
  
  Fig 7: Tester Specification
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 8: Disconnecting A ECU And R16 Speaker Connectors
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step
CHECK MICROPHONE ASSY
1. Check that the malfunction disappears when a normal microphone is installed (see MAYDAY SYSTEM ).
  1. If the malfunction does not disappear, proceed to A.
  2. If the malfunction disappears, proceed to B.
B: REPLACE MICROPHONE ASSY (See MAYDAY SYSTEM )

A: Go to next step
CHECK MICROPHONE AMPLIFIER ASSY
1. Check that the malfunction disappears when a normal microphone amplifier is installed (see MAYDAY SYSTEM ).
  1. If the malfunction does not disappear, proceed to A.
  2. If the malfunction disappears, proceed to B.
B: REPLACE MICROPHONE AMPLIFIER ASSY (See MAYDAY SYSTEM )

A: Go to next step
CHECK REAR SPEAKER ASSY (REAR DOOR LH)
1. Check that sound is emitted from the rear door speaker LH when the radio switch is ON.
OK: Radio sound is emitted from rear door speaker LH.

NG: GO TO AUDIO SYSTEM (See PRECAUTION )

OK: Go to next step.
CHECK TELEPHONE TRANSCEIVER ASSY
1. Check that the malfunction disappears when a normal telephone transceiver is installed (see MAYDAY SYSTEM ).
  1. If the malfunction does not disappear, proceed to A.
  2. If the malfunction disappears, proceed to B.
B: REPLACE TELEPHONE TRANSCEIVER ASSY (See MAYDAY SYSTEM )

A: Go to next step

REPLACE TELEPHONE ECU ASSY (See MAYDAY SYSTEM )