Engine Imobilizer: Overview Lexus RX II рестайлинг

SYSTEM DESCRIPTION

The engine immobilizer system has been designed to prevent the vehicle from being stolen.

This system uses a transponder key ECU that stores the key code of the authorized ignition key. If an attempt is made to start the engine using a non-authorized key, the transponder key ECU sends a signal to the hybrid vehicle control ECU to prohibit fuel delivery and ignition, effectively disabling the engine.

DESCRIPTION

This DTC will be output if the transponder key ECU does not detect that the unlock warning switch is on even when the ignition switch is on (Under the normal conditions, the unlock warning switch is on when the ignition switch is on).

DTC NO. DETECTION CONDITION CHART

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1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester (with CAN VIM) to the DLC3. Turn the ignition switch on and turn the intelligent tester main switch on. Select KEY SW in the DATA LIST and read the value displayed on the intelligent tester. Transponder key ECU: DIAGNOSTIC TROUBLE CODE CHART Item Measurement Item/Display (Range) Normal Condition Diagnostic Note KEY SW Unlock warning switch signal /ON or OFF ON: Key is in ignition key cylinder OFF: No key is in ignition key cylinder - OK: Both ON (Key is in ignition key cylinder) and OFF (No key in ignition key cylinder) appears on the screen OK: REPLACE TRANSPONDER KEY ECU ASSEMBLY NG: Go to next step
2. INSPECT UNLOCK WARNING SWITCH ASSEMBLY Remove the unlock warning switch. Measure the resistance according to the value(s) in the table below. Resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Switch Condition Specified Condition 1-2 Switch pushed (Key set) Below 1 ohms Switch free (Key removed) 10 kohms or higher NG: REPLACE UNLOCK WARNING SWITCH ASSEMBLY OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - UNLOCK WARNING SW ASSEMBLY) Disconnect the T9 ECU and K4 switch connectors. Measure the resistance according to the value(s) in the table below. Resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition T9-3 (KSW) - K4-2 Below 1 ohms T9-3 (KSW) - Body ground 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SW ASSEMBLY - BODY GROUND) Measure the resistance according to the value(s) in the table below. Resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition K4-1 - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE TRANSPONDER KEY ECU ASSEMBLY

The transponder key coil is built into the transponder key amplifier and receives a key code signal from the transponder chip in the key. This signal is amplified by the amplifier, and output to the transponder key ECU.

DTC NO. DETECTION CONDITION CHART

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1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester (with CAN VIM) to the DLC3. Turn the ignition switch on and turn the intelligent tester main switch on. Select ANTENNA COIL in the DATA LIST and read the value displayed on the intelligent tester. Transponder key ECU: DIAGNOSTIC TROUBLE CODE CHART Item Measurement Item/Display (Range) Normal Condition Diagnostic Note ANTENNA COIL Antenna coil condition /NORMAL or FAIL NORMAL: Antenna coil is normal. FAIL: Antenna coil is malfunctioning. - OK: NORMAL (Antenna coil is normal) appears on the screen. OK: REPLACE TRANSPONDER KEY ECU ASSEMBLY NG: Go to next step
2. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY TRANSPONDER KEY AMPLIFIER) Disconnect the T9 ECU and T8 switch connectors. Measure the resistance according to the value(s) in the table below. Resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition T9-9 (VC5) - T8-1 (VC5) Below 1 ohms T9-10 (CODE) - T8-4 (CODE) T9-12 (TXCT) - T8-5 (TXCT) T9-13 (AGND) - T8-7 (GND) T9-9 (VC5) or T8-1(VC5) - Body ground 10 kohms or higher T9-10 (CODE) or T8-4 (CODE) - Body ground T9-12 (TXCT) or T8-5 (TXCT) - Body ground T9-13 (AGND) or T8-7 (GND) - Body ground NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. INSPECT TRANSPONDER KEY ECU ASSEMBLY Reconnect the T9 ECU and T8 amplifier connectors. Measure the voltage according to the value(s) in the table below. Voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition T9-9 (VC5) - Body ground No key is in ignition key cylinder Below 1 V Key is in ignition key cylinder 4.6 to 5.4 V Measure the resistance according to the value(s) in the table below. Resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition T9-13 (AGND) - Body ground Always Below 1 ohms NG: REPLACE TRANSPONDER KEY ECU ASSEMBLY OK: Go to next step
4. CHECK OPERATION OF TRANSPONDER KEY AMPLIFIER After replacing the transponder key amplifier with a normally functioning transponder key amplifier, check that the hybrid control system starts. OK: Hybrid control system starts. NG: REPLACE TRANSPONDER KEY ECU ASSEMBLY OK: END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)

This DTC is output when a malfunction is found in the key during the key code registration or the key code is not registered normally. Replace the key when the key code registration is not performed normally and this DTC is detected.

WAVEFORM REFERENCE CHART

This DTC is output when a key with an incomplete key code is inserted into the ignition key cylinder.

DTC NO. DETECTION CONDITION CHART

This DTC is output when a key with a code that has not been registered in the ECU is inserted into the ignition key cylinder.

DTC NO. DETECTION CONDITION CHART

These codes are stored in the memory when a key that does not have a transponder chip is inserted or if communication between the key and transponder key ECU is impossible.

DTC NO. DETECTION CONDITION CHART

This DTC is output when an error occurs in normal communication.

HINT

Some noise found in the communication line.

DTC NO. DETECTION CONDITION CHART

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1. CHECK KEY Check whether the ignition key being used is near other ignition keys, as shown in the illustration. Also, check whether the key ring is in contact with the key grip. Result RESULT REFERENCE Result Proceed to Key is near other keys and/or key ring is in contact with key grip. A Key is not near other keys and / or key ring is not in contact with key grip. B B: GO TO step 3 A: Go to next step
2. CHECK FOR DTC Delete the DTC (See «DTC CHECK/CLEAR» ). Insert the key into the ignition key cylinder. Check that no code is output. OK: No DTC is output. OK: NO PROBLEM NG: Go to next step
3. CHECK TRANSPONDER KEY AMPLIFIER Using an oscilloscope or the intelligent tester, check the waveform between the terminals of the T8 amplifier and T9 ECU connector. Check that no noise is included in the waveform (an example of noise is shown on the left). Check that no noise is included in the waveform (an example of noise is shown on the left). Result TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition T8-4 (CODE) - T9-10 (CODE) No noise is present TOOL REFERENCE Tool Setting 2 V/DIV., 20 ms/DIV. Condition Key inserted into ignition key cylinder. NG: FIND CAUSE OF NOISE AND REMOVE NOISE OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER) Disconnect the T9 ECU and T8 amplifier connectors. Measure the resistance according to the value(s) in the table below. Resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition T9-10 (CODE) - T8-4 (CODE) Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. CHECK OPERATION OF TRANSPONDER KEY AMPLIFIER After replacing the transponder key amplifier with a normally functioning transponder key amplifier, check that the hybrid control system starts. OK: Hybrid control system starts NG: REPLACE TRANSPONDER KEY ECU ASSEMBLY OK: END (TRANSPONDER KEY AMPLIFIER DEFECTIVE)

These DTCs are output when the hybrid vehicle control ECU detects errors in communication between the transponder key ECU and the hybrid vehicle control ECU, and in the communication lines. These DTCs are also output when a hybrid control system start is attempted while the ECU communication ID between the transponder key ECU and the hybrid vehicle control ECU are different. Before troubleshooting for DTCs, make sure that there is no DTC detected in the transponder key ECU. If there is key code related DTC detected in the transponder key ECU, repair it first.

DTC NO. DETECTION CONDITION CHART

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1. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - HYBRID VEHICLE CONTROL ECU) Disconnect the T9 ECU and H29 hybrid vehicle control ECU connectors. Measure the resistance according to the value(s) in the table below. Resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition T9-6 (EFIO) - H29-22 (IMI) Below 1 ohms T9-7 (EFII) - H29-28 (IMO) T9-6 (EFIO) or H29-22 (IMI) - Body ground 10 kohms or higher T9-7 (EFII) or H29-28 (IMO) - Body ground Measure the voltage according to the value(s) in the table below. Voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition T9-6 (EFIO) or H29-22 (IMI) - H31-5(E1) Ignition switch on Below 1 V T9-7 (EFII) or H29-28 (IMO) - H31-5(E1) NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
2. RE-REGISTRATION ECU COMMUNICATION ID (TRANSPONDER KEY ECU ASSEMBLY HYBRID VEHICLE CONTROL ECU) Re-register the ECU communication ID (See 5 ). Check that the hybrid control system starts. OK: Hybrid control system starts. OK: NO PROBLEM NG: Go to next step
3. CHECK OPERATION OF TRANSPONDER KEY ECU ASSEMBLY After replacing the transponder key ECU assembly with a normally functioning transponder key ECU assembly, check that the hybrid control system starts. OK: Hybrid control system starts. NG: REPLACE HYBRID VEHICLE CONTROL ECU OK: END (TRANSPONDER KEY ECU ASSEMBLY DEFECTIVE)

This circuit provides power to the transponder key ECU.

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1. CHECK FUSES (MPX-B, IGN, AM2 No.1) Remove the MPX-B, IGN fuses from the instrument panel J/B. Remove the AM2 No.1 fuse from the fusible link block. Measure the resistance of the fuses. Resistance: Below 1 ohms NG: CHECK FOR SHORT IN ALL HARNESS AND CONNECTOR CONNECTED TO FUSE AND REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY BATTERY) Disconnect T9 ECU connector. Measure the voltage according to the value(s) in the table below. Voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition T9-2 (IG2) - Body ground Ignition switch off Below 1 V T9-2 (IG2) - Body ground Ignition switch on 10 to 14 V T9-1 (CPUB) - Body ground Always 0 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - BODY GROUND) Measure the resistance according to the value(s) in the table below. Resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition T9-14 (GND) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

See also:
• HYBRID CONTROL SYSTEM
• ADJUSTMENT