Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

Check transmission wire.
PREPARATION:

Disconnect the transmission wire connector.

CHECK:

Measure resistance between S4 of transmission wire and body ground.

OK:

Resistance: 11 - 15 Ω at 20 °C (68 °F)
1. NG : Go to step 3 .
  
  Fig 1: Measuring Resistance Between S4 Of Transmission Wire And Body Ground
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. OK : Go to next step.
Measure resistance between terminals S4 of ECM and body ground.
PREPARATION:
1. Connect the transmission wire connector.
2. Remove the ECM hood.
3. Disconnect the connector from ECM.
  CHECK:
  
  Measure resistance between terminals S4 and E1 of ECM.
  
  OK:
  
  Resistance: 11 - 15 Ω at 20 °C (68 °F)
1. NG : Repair or replace the harness or connector (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
  
  Fig 2: Measuring Resistance Between Terminals S4 And E1 Of ECM
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. OK : Check and replace the ECM (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
Check shift solenoid valve No. 4.
PREPARATION:

Remove the shift solenoid valve No. 4 (See VALVE BODY ASSEMBLY ).

CHECK:
1. Measure resistance between terminal and solenoid body.
2. Connect positive (+) lead to terminal of solenoid connector and negative (-) lead to solenoid body.
  OK:
  1. (a) Resistance: 11 - 15 Ω at 20 °C (68 °F)
  2. (b) The solenoid makes an operating noise.
    
    Fig 3: Measuring Resistance Between Terminal And Solenoid Body
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG : Replace the shift solenoid valve No. 4. (See VALVE BODY ASSEMBLY ).
2. OK : Repair or replace the transmission wire (See ATF TEMPERATURE SENSOR ).