Section 367 (Cruise Control System - Diagnosis): Pre-Check

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.

DIAGNOSIS SYSTEM
1. Check the indicator.
  1. Turn the ignition switch ON.
  2. Check that the CRUISE MAIN indicator light comes on when the cruise control main switch is turned on, and that the indicator light goes off when the main switch is turned OFF.
    HINT:
    
    If the indicator check result is not normal, proceed to troubleshooting (See HOW TO PROCEED WITH TROUBLESHOOTING ) for the combination meter section.
    
    Fig 1: Identifying Cruise Main Indicator Light
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the DTC.
  HINT:
  
  If a malfunction occurs in the vehicle speed sensors or actuator, etc. during cruise control driving, the ECU actuates AUTO CANCEL of the cruise control and turns on and off the CRUISE MAIN indicator light to inform the driver of a malfunction. At the same time, the malfunction is stored in memory as a diagnostic trouble code.
  
  Fig 2: Indicator Light Pattern
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Output of DTC using diagnosis check wire.
  1. Turn the ignition switch ON.
  2. Using SST, connect terminals Tc and CG of DLC3.
    SST 09843-18020
  3. DTC is shown in figures on the multi-display on the combination meter.
    
    Fig 3: Identifying Connector Terminals
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
USING LEXUS HAND-HELD TESTER
1. Hook up the LEXUS hand-held tester to the DLC3.
2. Monitor the ECU data by following the prompts on the tester screen.
  HINT:
  
  LEXUS hand-held tester has a "Snapshot" function which records the monitored data.
  
  Please refer to the LEXUS hand-held tester operator's manual for further details.
  
  Fig 4: Connecting Hand-Held Tester To DLC3
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DTC CLEAR
1. The DTCs and freezed frame data will be erased by either action.
  Opening the OBD II scan tool (complying with SAE J1978) or LEXUS hand-held tester to erase the codes. (See the OBD II scan tool's instruction book for operating instructions.)
2. Remove the EFI fuse from engine room J/B for 10 seconds or more.