Lexus NX: Immobiliser System does not Operate Properly
DESCRIPTION
The immobiliser system compares the ID code that is registered in the certification ECU (smart key ECU assembly) with the ID code of the transponder chip that is embedded in the electrical key transmitter sub-assembly.
WIRING DIAGRAM
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CAUTION / NOTICE / HINT
NOTICE:
- When using the Techstream with the power switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus: Body Electrical / Smart Access. While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
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The immobiliser system uses the LIN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the immobiliser system after confirming that the communication systems are functioning properly.
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Before replacing the hybrid vehicle control ECU, ID code box (immobiliser code ECU) or certification ECU (smart key ECU assembly), refer to Registration.
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- After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation."
HINT:
If an immobiliser system or hybrid control system DTC is output, first perform troubleshooting for the immobiliser system or hybrid control system DTC.
PROCEDURE
| 1. | CHECK FOR DTC |
(a) Check for DTCs.
Body Electrical > Smart Access > Trouble Codes Powertrain > Hybrid Control > Trouble Codes| Result | Proceed to |
|---|---|
| DTCs are not output | A |
| DTCs are output | B |
| B | .gif) | GO TO DIAGNOSTIC TROUBLE CODE CHART |
|
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| 2. | CHECK WHETHER HYBRID CONTROL SYSTEM STARTS |
(a) Check that the hybrid control system starts 5 seconds after the power switch turned on (READY).
OK:
Hybrid control system starts normally.
| OK | | USE SIMULATION METHOD TO CHECK |
|
| 3. | CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - HYBRID VEHICLE CONTROL ECU) |
(a) Disconnect the I26 ID code box (immobiliser code ECU) connector.
(b) Disconnect the I116 hybrid vehicle control ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| I26-3 (EFII) - I116-23 (IMO) | Always | Below 1 Ω |
| I26-4 (EFIO) - I116-22 (IMI) | Always | Below 1 Ω |
| I26-3 (EFII) or I116-23 (IMO) - Body ground | Always | 10 kΩ or higher |
| I26-4 (EFIO) or I116-22 (IMI) - Body ground | Always | 10 kΩ or higher |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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| 4. | REGISTER ECU COMMUNICATION ID |
(a) Register the ECU communication ID.
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| 5. | CHECK WHETHER HYBRID CONTROL SYSTEM STARTS |
(a) Check that the hybrid control system starts.
OK:
Hybrid control system starts normally.
| OK | | END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE) |
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| 6. | REPLACE ID CODE BOX (IMMOBILISER CODE ECU) |
(a) Replace the ID code box (immobiliser code ECU) with a new one.
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| 7. | REGISTER RECOGNITION CODE |
(a) Register the recognition codes in the ECUs.
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| 8. | REGISTER ECU COMMUNICATION ID |
(a) Register the ECU communication ID.
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| 9. | CHECK WHETHER HYBRID CONTROL SYSTEM STARTS |
(a) Check that the hybrid control system starts.
OK:
Hybrid control system starts normally.
| OK | | END (ID CODE BOX (IMMOBILISER CODE ECU) WAS DEFECTIVE) |
| NG | | GO TO HYBRID CONTROL SYSTEM |
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Precaution
PRECAUTION PRECAUTIONS DURING REPLACEMENT NOTICE: When replacing electronic parts, if there is a possibility that your body may contact a circuit board, etc., use the recommended tools and observe all
Components
COMPONENTS ILLUSTRATION *1 DECK FLOOR BOX LH *2 NO. 3 DECK BOARD SUB-ASSEMBLY *3 REAR DECK FLOOR BOX *4 NEGATIVE AUXILIARY BATTERY TERMINAL N*m (kgf*cm, ft.*lbf): Specified
SEE MORE:
Parts Location
PARTS LOCATION ILLUSTRATION *1 ENGINE ROOM RELAY BLOCK
- AM2 FUSE
*2 WIRELESS DOOR LOCK BUZZER *3 DOOR CONTROL RECEIVER - - ILLUSTRATION *A w/o Power Back Door System *B w/ Power Back Door System *1 BACK DOOR COURTESY LIGHT SWITCH ASSEMBLY *2 BACK DOO
Reassembly
REASSEMBLY CAUTION / NOTICE / HINT HINT:
Use the same procedure for the RH and LH sides.
The procedure listed below is for the LH side.
PROCEDURE 1. INSTALL OUTER MIRROR RETRACTOR LH (a) Install a new frame sub-assembly with the 2 screws. (b) Wind vinyl tape around the harness
