OBD II scan tool (excluding hand-held tester):

INSPECT THROTTLE POSITION SENSOR
1. Disconnect the T1 throttle position sensor connector.
2. Measure the resistance between the terminals of the throttle position sensor.
  Standard:
  
  Fig 1: Identifying T1 throttle Position Sensor Connector terminals (Component side)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Reconnect the throttle position sensor connector.
  
  Fig 2: Tester Connections Specified Condition Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: REPLACE THROTTLE POSITION SENSOR
2. OK: Go to next step.
CHECK HARNESS AND CONNECTOR(THROTTLE POSITION SENSOR - ECM)
1. Disconnect the E3 ECM connector.
2. Measure the resistance between the terminals of the E3 ECM connector.
  Standard:
  
  Fig 3: E3 ECM Connectors Terminals Specified Condition Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check the resistance between the terminals of the E3 ECM connector.
  Standard (Check for short):
  
  Fig 4: Identifying E3 ECM Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Reconnect the ECM connector.
  
  Fig 5: E3 ECM Connectors Terminals Specified Condition Table (Check For Short)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
2. OK: REPLACE ECM (See REPLACEMENT )