Inspection Procedure

1. Disconnect the distance control ECU and laser sensor connectors.
Fig 1: Disconnecting Distance Control ECU And Laser Sensor Connectors
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value (s) in the table below.

   Standard resistance 

   RESISTANCE SPECIFICATION
   
   

   Tester Connections	Condition	Specified value
   A20-23 (LRRD) - A36-4 (LRRD)	Always	Below 1 Ω
   A20-13 (IGB) - A36-5 (IGB)	Always	Below 1 Ω
   A20-23 (LRRD) - Body ground	Always	10 kΩ or higher
   A20-13 (IGB) - Body ground	Always	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to Next Step 

1. Reconnect the cruise control ECU (distance control ECU) connector.
2. Turn the ignition switch on (IG).
3. Measure the voltage according to the value (s) in the table below.

   Standard voltage 

   VOLTAGE SPECIFICATION
   
   

   Tester Connections	Condition	Specified value
   A20-13 (IGB) - Body ground	Ignition SW ON (IG)	10 to 14 V

4. Check the signal waveform between terminal LRRD (A20-23) of the cruise control ECU (distance control ECU) and body ground.

   OK: 

   A waveform similar to that in the illustration to the left is output. 

   HINT:

   • Gauge set: 2 V/DIV, 5 ms/DIV
   • Condition: Ignition switch on (IG)

Fig 2: Signal Waveform Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE CRUISE CONTROL ECU 

OK: REPLACE LASER SENSOR