Diagnosis System

WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.

DESCRIPTION
The ECU controls the cruise control system of the vehicle. The data and DTCs relating to the cruise control system can be read from the DLC3 of the vehicle. If either DTC is not displayed when checking for DTCs, there may be a problem with the combination meter or the CAN communication and multiplex communication system. Use the intelligent tester to check and solve the problem.

CHECK DLC3

The vehicle's hybrid vehicle control ECU uses ISO 9141-2 for communication. The terminal arrangement of DLC3 complies worth SAE J1962 and matches the ISO 9141-2 format.

Fig 1: Identifying Terminals Of DLC3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

DLC TERMINALS DESCRIPTION AND SPECIFIED CONDITION

Terminal No.	Terminal Description	Condition	Specified Condition
4	Chassis ground	Always	Below 1 Ω
7	Bus "+" line	During transmission	Pulse generation
16	Battery positive	Always	11 to 14 V

HINT:

Connect the cable of the intelligent tester to the DLC3, turn the ignition switch on and attempt to use the tester. If the display indicates that a communication error has occurred there is a problem either with the vehicle or with the tester.

If communication is normal when the tester is connected to another vehicle, inspect the DLC3 on the original vehicle.
If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual.

CHECK INDICATOR
1. Turn the ignition switch on.
  
  Fig 2: Identifying Cruise Main Indicator Light
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check that the CRUISE main indicator light illuminates when the cruise control main switch is turned ON, and that the indicator light turns off when the main switch is turned OFF. If the results are not as specified, inspect the CRUISE MAIN INDICATOR LIGHT CIRCUIT .
  
  Fig 3: Identifying Cruise Main Indicator Light Blinking Pattern
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  HINT:
  - While driving with cruise control, the hybrid vehicle control ECU activates AUTO CANCEL of the cruise control system when a malfunction in one of the following occurs: vehicle speed sensors, stop light switch or other related parts. When AUTO CANCEL is activated, the CRUISE main indicator light outputs the blinking pattern shown to the left. At the same time, data of the malfunction is stored as a DTC.