Engine Immobilizer System: Pre-Check

1. DIAGNOSIS SYSTEM 
   1. Description
      1. The ECM controls the function of the immobilizer system on the vehicle.

         Data of the immobilizer system and the Diagnostic Trouble Code (DTC) can be read in the Data Link Connector 3 (DLC3) of the vehicle. When trouble occurs in the immobilizer system, even though the security Indicator lamp does not come on, DTCs can be checked.

         Therefore, when the immobilizer system seems to be malfunctioning, use the hand-held tester to check for a malfunction and repair it.

   2. Inspect the DLC3.

      The vehicle's ECM uses the ISO 9141-2 communication protocol. The terminal arrangement of the DLC3 complies with the SAE J1962 and matches the ISO 9141-2 format.

   Fig 1: Identifying Data Link Connector 3 (DLC3) Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard: 

   INSPECT DLC3 SPECIFIED CONDITION
   
   

   Terminal No.	Condition	Specified Condition
   7 (Bus + Line) - 5 (Signal ground)	During communication	Pulse generation
   4 (Chassis Ground) - Body ground	Always	Below 1 Ω
   5 (Signal Ground) - Body ground	Always	Below 1 Ω
   16 (B+) - Body ground	Always	10 to 14 V

   HINT:

   If the screen displays UNABLE TO CONNECT TO VEHICLE after you have connected the cable of the hand-held tester to the DLC3, turned the ignition switch ON and used the hand-held tester, the problem may be on the vehicle side or the tester side.

   • If communication is normal when the tester is connected to other vehicle, inspect the DLC3 of the original vehicle.
   • If communication is still impossible when the tester is connected to another vehicle, the problem may be in the tester itself, so consult the Service Department listed in the tester's instruction manual.
2. Using hand-held tester: 

   CHECK DTC 

   1. Checking DTCs.
      1. Connect the hand-held tester to DLC3.
      2. Turn the ignition switch ON.
      3. Read DTCs by following the prompts on the tester screen.

      HINT:

      Refer to the hand-held tester operator's manual for further details.

   2. Clear the DTCs from memory.
      1. Connect the hand-held tester to DLC 3.
      2. Turn the ignition switch ON.
      3. Erase DTCs by following the prompts on the tester screen.

   HINT:

   Refer to the hand-held tester operator's manual for further details.

3. CHECK DIAGNOSIS 
   1. Using the hand-held tester, check for DTCs.
      NOTE: Hand-held tester only:
      When the diagnosis system is switched from normal mode to check mode, all the DTCs and freeze frame data recorded in the normal mode are erased. So before switching modes, always check the DTCs and freeze frame data, and make a note of them.
      1. Prepare the hand-held tester.
      2. Connect the hand-held tester to the DLC3 under the instrument panel lower pad.
      3. Turn the ignition switch ON and push the hand-held tester switch ON.
      4. Use the hand-held tester to check for DTCs and freeze frame data, and make a note of them (For operating instructions, see the hand-held tester instruction book).
      5. Confirm the details of the DTCs.
   2. Either of the following procedures will erase the DTCs and freeze frame data.
      1. Operating the hand-held tester to erase the codes (See the hand-held tester instruction book for operating instructions).
      2. Disconnecting the battery terminals or ECU-B fuse.
4. DATA LIST 

   HINT:

   Using to the DATA LIST displayed on the hand-held tester, you can read the value of the switch, sensor, actuator, etc. without parts removal. Reading the DATA LIST as the first step of troubleshooting is one way to shorten the labor time.

   1. Connect the hand-held tester to the DLC3.
   2. Turn the ignition switch ON.
   3. Read the DATA LIST, according to the display on the tester.

      Transponder key ECU assy: 

   DATA LIST
   
   

   Item	Measurement Item/Display (Range)	Normal Condition	Diagnostic Note
   KEY SW	unlock warning SW signal/ON or OFF	OFF: Key is in IG key cylinder ON: No key is in IG key cylinder	-
   IG SW	IG SW signal/ON or OFF	OFF: IG SW is ON or START position ON: IG SW is OFF or ON position	-
   IMMOBILIZER	Immobilizer system status/SET or UNSET	UNSET: Without key SET: Ignition switch ON	-
   RESPONSE	Transponder chip data/NG or OK	NG: Data error OK: Data OK	-
   FRAME	Transponder chip data/NG or OK	NG: Data error OK: Data OK	-
   SERIAL NUMBER	Transponder chip data/NG or OK	NG: Data error OK: Data OK	-
   ENCRYPT CODE	Transponder chip data/NG or OK	NG: Data error OK: Data OK	-
   STATUS	Transponder chip data/NG or OK	NG: Data error OK: Data OK	-
   BCC	Transponder chip signal/NG or OK	NG: Incorrect data sending OK: Correct data sending	-
   SUB KEY	Sub key code signal/NOMATCH or MATCH	NOMATCH: Nomatch sub key code is sent MATCH: Sub key code is sent	-
   MASTER KEY	Master key code signal/NOMATCH or MATCH	NOMATCH: Nomatch Master key code is sent MATCH: Master key code is sent	-
   REGIST SUB CODE	Number of registered sub-key/min. 0, max. 15	Number of registered sub-key	-
   REGIST MAS CODE	Number of registered master key/min. 0, max. 15	Number of registered master key	-
   REG CODE SPACE	Memory space for key codes registration/NOT FUL or FULL	NOT FUL: Possible to resister more key code FULL: Impossible to register key code any more	-
   ANTENNA COIL	Antenna coil condition/NORMAL or FAIL	Normal: Antenna coil is normal FAIL: Antenna coil is abnormal	-

5. ACTIVE TEST 

HINT:

Performing the ACTIVE TEST using the hand-held tester allows you to operate the relay, VSV, actuator, etc. without parts removal. Performing the ACTIVE TEST as the first step of troubleshooting is one way to shorten the labor time.

1. Connect the hand-held tester to the DLC3.
2. Turn the ignition switch ON.
3. Perform the ACTIVE TEST, according to the display on the tester.

   Transponder key ECU assy: