Inspection Procedure

WARNING: This page is about a different car, the 2005 Toyota Sienna. However, it is still accessible from the selected car via links, so may be relevant.

CHECK WIRE HARNESS AND CONNECTOR (DISTANCE CONTROL ECU - LASER RADAR SENSOR)
1. Check for an open or short circuit in harness and connector between the distance control ECU and the laser radar sensor (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
1. NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR
2. OK: Go to next step
INSPECT DISTANCE CONTROL ECU ASSY
1. Remove the distance control ECU with connector.
2. Turn the ignition switch ON.
3. Measure the voltage between terminal IGB (D2-13) of distance control ECU and body ground.
  Standard: 10 to 14V
  
  Fig 1: Measuring Voltage Between Terminal IGB (D2-13) Of Distance Control ECU & Body Ground
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Check the signal waveform between terminal LRRD (D2-23) of distance control ECU and body ground.
  Standard:
  
  The connect signal waveform appears, as shown in Fig 2 .
HINT:
- Gauge set: 2 V/DIV, 5 ms/DIV
- Condition: Ignition switch ON
Fig 2: Identifying Signal Waveform Between Terminal LRRD (D2-23) Of Distance Control ECU & Body Ground
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: REPLACE DISTANCE CONTROL ECU ASSY (see DISTANCE CONTROL ECU ASSY )
2. OK: REPLACE LASER RADAR SENSOR