Engine Immobilizer System - Diagnostics: Pre-Check

DIAGNOSIS SYSTEM
1. Description
  ECM controls the function of immobilizer on this vehicle. Data of the immobilizer or DTC can be read form DLC3 of the vehicle. When a trouble occurs on immobilizer, MIL does not light up but DTC inspection is performed.
  
  Therefore when there seems to be a trouble on immobilizer, use LEXUS hand-held tester or SST to check and troubleshoot it.
  
  Fig 1: Identifying LEXUS Hand-Held Tester
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Inspect the DLC3.
  The vehicle's ECM uses ISO 9141 -2 for communication.
  
  The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.
  
  Fig 2: Connecting LEXUS Hand-Held Tester To DLC3 Under Instrument Panel Lower Pad
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 3: Tester Specification
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  HINT:
  
  If the display shows "UNABLE TO CONNECT TO VEHICLE" as connecting the LEXUS hand-held tester to the DLC3 and turn the ignition ON, there is a problem either on the vehicle or on the tool.
  - If communication is normal when connecting the tool to another vehicle, inspect DLC3 on the original vehicle.
  - If communication is still not possible when connecting the tool to another vehicle, the problem is probably in the tool itself. Consult the Service Department listed in the to. instruction manual in that case.
INSPECT DIAGNOSIS
1. Check the DTC (Using LEXUS hand-held tester).
  1. Prepare the LEXUS hand-held tester.
  2. Connect the LEXUS hand-held tester to DLC3 under the instrument panel lower pad.
  3. Turn the ignition switch ON and turn the LEXUS hand-held tester switch ON.
  4. Use the LEXUS hand-held tester to check the DTCs and freeze frame data; note them down (For operating instructions, see the LEXUS hand-held tester instruction book).
  5. See DIAGNOSTIC TROUBLE CODE CHART to confirm the details of the DTCs.
    
    Fig 4: Connecting LEXUS Hand-Held Tester To DLC3 Under Instrument Panel Lower Pad
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the DTC (Using diagnosis check wire).
  1. Turn ignition switch ON.
  2. Using SST, connect between terminals 11 (TC) and 3 (E1) of DLC 1.
    SST 09843-18020
  3. Read the diagnostic trouble code from malfunction indicator lamp (MIL) .
    HINT:
    - If a DTC is not output, check the TC terminal circuit (2JZGE: See TC TERMINAL CIRCUIT , 3UZ-FE: See TC TERMINAL CIRCUIT ).
    - ECM controls the immobilizer function on this vehicle, DTC is out put with engine data.
      
      Fig 5: Connecting Between Terminals (TC) And (E1) Of DLC 1
      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    - As an example, the blinking patterns for codes; normal, 99 are shown in the charts.
      
      Fig 6: Identifying Normal Codes Blinking Patterns
      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      
      Fig 7: Identifying Malfunction Codes Blinking Patterns
      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. When DTC "99" is output, there is a trouble of immobilizer. Start troubleshooting referring to PROBLEM SYMPTOMS TABLE.
  5. After completing the check, disconnect the SST from the DLC3 and turn off the display.
    HINT:
    
    In the event of 2 or more malfunction codes, indication will begin from the smaller numbered code and continue in order to the larger.
3. Clear the DTC.
  The following operations will erase the DTCs and freeze frame data.
  - Operating the LEXUS hand-held tester to erase the codes (See the LEXUS hand- held tester instruction book for operating instructions).
  - Disconnecting the battery terminals or EFI fuse for 1 minute or more.