Engine Immobilizer System - Diagnostics Toyota Highlander I

HOW TO PROCEED WITH TROUBLESHOOTING

Troubleshoot in accordance with the procedure on the following pages.

1. Vehicle Brought To Workshop
2. Customer Problem Analysis (See «CUSTOMER PROBLEM ANALYSIS CHECK»(/toyota/highlander/i-2001-2003/remont/door-locks-anti-theft-systems/#engine-immobilizer-system-diagnostics) ) .
3. Check And Clear DTC (Pre-Check) (See «PRE-CHECK»(/toyota/highlander/i-2001-2003/remont/door-locks-anti-theft-systems/#engine-immobilizer-system-diagnostics) ) .
4. Problem Symptom Confirmation Symptom does not occur: go to next step. Symptom occurs: go to step 6.
5. Symptom Simulation
6. DTC Check (See «PRE-CHECK»(/toyota/highlander/i-2001-2003/remont/door-locks-anti-theft-systems/#engine-immobilizer-system-diagnostics) ) . Normal Code: See «PROBLEM SYMPTOMS TABLE»(/toyota/highlander/i-2001-2003/remont/door-locks-anti-theft-systems/#engine-immobilizer-system-diagnostics__problem-symptoms) ). Malfunction Code: See «DIAGNOSTIC TROUBLE CODE CHART»(/toyota/highlander/i-2001-2003/remont/door-locks-anti-theft-systems/#engine-immobilizer-system-diagnostics) .
7. Circuit Inspection And Part Inspection (See «DTC B2795 UNMATCHED KEY CODE»(/toyota/highlander/i-2001-2003/remont/door-locks-anti-theft-systems/#engine-immobilizer-system-diagnostics) ) .
8. Identification Of Problem
9. Repair
10. Confirmation Test

End

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1. Diagnosis System Description ECM controls the function of the immobilizer on this vehicle. Data of the immobilizer or Diagnostic Trouble Code (DTC) can be read in the Data Link Connector 3 (DLC3) of the vehicle. When a trouble occurs in the immobilizer, Malfunction Indicator Lamp (MIL) does not come on but DTC inspection is performed. Therefore when there seems to be a trouble with immobilizer, use hand-held tester or SST to check and troubleshoot it. Inspect the DLC3. The vehicle's ECM uses ISO 14230 for communication. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 14230 format. NOTE: If your display shows "UNABLE TO CONNECT TO VEHICLE" when you have connected the cable of the hand-held tester to the DLC3, turned the ignition switch ON and operated the hand-held tester, there is a problem on the vehicle side or tool side. If the communication is normal when the tool is connected to another vehicle, inspect the DLC3 of the original vehicle. If the communication is still impossible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.
2. Inspect Diagnosis Using hand-held tester, check the DTC. NOTE: Hand-held tester only: When the diagnosis system is switched from the normal mode to the check mode, all the DTCs and freeze frame data recorded in the normal mode will be erased. So before switching the modes, always check the DTCs and freeze frame data, and note them down. Prepare the hand-held tester. Connect the hand-held tester to the DLC3 under the instrument panel lower pad. Turn the ignition switch ON and push the hand-held tester switch ON. Use the hand-held tester to check the DTCs and freeze frame data; note them down. (For operating instructions, see the hand-held tester instruction book.) See «DIAGNOSTIC TROUBLE CODE CHART»(/toyota/highlander/i-2001-2003/remont/door-locks-anti-theft-systems/#engine-immobilizer-system-diagnostics) to confirm the details of the DTCs. Clear the DTC, and the following operations will erase the DTCs and freeze frame data. Operating the hand-held tester to erase the codes. (See the hand-held tester instruction book for operating instructions.) Disconnecting the battery terminals or EFI fuse. Using break-out-box and hand-held tester, measure the ECM terminal values. Connect the hand-held tester and break-out-box to the vehicle. Read the ECM input/output values by following the prompts on the tester screen. NOTE: Hand-held tester has a "snapshot" function. This records the measured values and is effective in the diagnosis of intermittent problems. Refer to the hand-held tester/brake-out-box operator's manual for further details.

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Note. To reduce unnecessary exchange of ECM, check that a trouble occurs with the original ECM, and then check the trouble is solved with a new ECM.

DIAGNOSTIC TROUBLE CODES (DTC) LIST

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PROBLEM SYMPTOMS

Problem Symptoms

Circuit Description

This DTC is output when an unregistered key is inserted.

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1. Delete DTC and insert all presently available keys to check whether engine starts or not . NOTE: When inserting the key that does not start the engine, DTC B2795 is stored in the memory. OK: No Problem NOTE: If the result is "OK", confirm whether or not the customer has ever inserted an unregistered key or the immobilizer key (with transponder chip) of other vehicle in the ignition key cylinder, and find out a cause of detecting DTC. NG: Register Key That Does Not Start Engine .

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For a complete system wiring diagram, see ANTI-THEFT.

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1. Delete DTC and insert all presently available keys to check whether engine starts or not . A: All keys start engine . B: A specific key does not start engine. In this case, DTC DTC B2796 is stored in memory . C: All keys do not start engine. In this case, DTC DTC B2796 is stored in memory . A : No problem at this time . NOTE: If the result is "A", confirm whether or not the customer has ever inserted a key (without transponder chip) of other vehicle in the ignition key cylinder, and find out a cause of detecting DTC. B : Transponder chip of a specific key is defective and replace key . C : Go to next step .
2. Check Transponder Key Amplifier OK: Go to next step. NG: Transponder Key Amplifier
3. Check wire harness (transponder key amplifier - ECM) Check the continuity between terminal CODE (E6-28) of the ECM connector and terminal CODE (T7-4) of the transponder key amplifier connector. Check the continuity between terminal RXCK (E6-19) of the ECM connector and terminal RXCK (T6-19) of the ECM connector and terminal RXCK (T7-3) of the transponder key amplifier connector. Check the continuity between terminal TXCK (E6-18) of the ECM connector and terminal TXCK (T7-5) of the transponder key amplifier connector. Standard: Continuity OK: Go to next step. NG: Repair or replace harness and connector.
4. Check transponder key amplifier Check that the transponder key amplifier operates normally after replacing it with a normal one. OK: Check transponder key amplifier. NG: Check and replace ECM (See «HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS»(ref-174461-S15605692682005040500000) ).

This code is detected when an error occurs in the normal communication.

(Example: Some noise is included in the communication line).

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For a complete system wiring diagram, see ANTI-THEFT.

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1. Check noise . Insert the already registered master key in the key cylinder. Using an oscilloscope or hand-held tester, check that noise is included in the CODE (E6-28) terminal of the ECM. Standard: No Noise Is Detected OK: Go to next step . NG: Find cause of noise and remove it.
2. Check transponder key amplifier. Check that the transponder key amplifier operates normally after the replacement. OK: Replace transponder key amplifier. NG: Check and replace ECM (See «HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS»(ref-174461-S15605692682005040500000) ).

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For a complete system wiring diagram, see ANTI-THEFT.

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1. Check wire harness (transponder key amplifier - ECM) Check the continuity between terminal CODE (E6-28) of the ECM connector and terminal CODE (T7-4) of the transponder key amplifier connector. Check the continuity between terminal RXCK (E6-19) of the ECM connector and terminal RXCK (T7-3) of the transponder key amplifier connector. Check the continuity between terminal TXCK (E6-18) of the ECM connector and terminal TXCK (T7-5) of the transponder key amplifier connector. Standard: Continuity OK: Go to next step. NG: Replace harness and connector
2. Check transponder key amplifier. Check that the transponder key amplifier operates normally after the replacement. OK: Replace transponder key amplifier NG: Check and replace ECM (See «HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS»(ref-174461-S15605692682005040500000) ).

This circuit provides power to operate the transponder key amplifier.

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For a complete system wiring diagram, see BODY COMPUTER.

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1. Inspect transponder key amplifier . Measure the voltage between terminals +B (T7-1) and +B (T7-7) of the transponder key amplifier connector. Voltage: 10 - 14 V OK: Proceed to next circuit inspection shown In «PROBLEM SYMPTOMS»(/toyota/highlander/i-2001-2003/remont/door-locks-anti-theft-systems/#engine-immobilizer-system-diagnostics) . NG: Go to next step .
2. Check Fuse (EFI) Check the continuity of the EFI fuse. Result: Continuity OK: Go to next step. NG: Check for short in all harness and components connected to EFI fuse.
3. Check wire harness (transponder key amplifier - ECM) Check the continuity between terminal +B (T7-1) of the transponder key amplifier connector and terminal +B (E5-16) of the ECM connector. Standard: Continuity OK: Check and replace transponder key amplifier (See «HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS»(ref-174461-S15605692682005040500000) ). NG: Check and replace harness and connector

When the engine immobilizer system is ready to be set, this circuit lights up the security indicator light. When the system has been set, it continually turns the security indicator light on for 0.8 seconds and turns it off for 1.2 seconds, thus the security indicator light blinks.

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For a complete system wiring diagram, see ANTI-THEFT.

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1. Check security indicator lamp assy . Remove the security indicator light. Check the security indicator light comes on when connecting the positive (+) lead to terminal 1 and the negative (-) lead to terminal 2 of the connector. Result: security indicator light comes on . OK: Go to next step. NG: Replace security indicator lamp assy.
2. Check wire harness (ECM - security indicator light) . Check the continuity between terminal IMLD (E5-22 on 1MZ-FE Engine) or IMLD (E6-26 on 2AZ-FE Engine) of the ECM connector and terminal 2 of the security indicator connector. Standard: Continuity OK: Go to next step. NG: Check and replace harness and connector.
3. Check wire harness (security indicator light - body ground). Check the continuity between terminal 1 of the security indicator light connector and the body ground. Standard: Continuity OK: Check and replace ECM (See «HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS»(ref-174461-S15605692682005040500000) ) NG: Check and replace security indicator lamp assy.

The key unlock warning switch comes on when the ignition key is inserted in the key cylinder and goes off when the ignition key is removed.

The ECU operates the key confinement prevention function while the key unlock warning switch is on.

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For a complete system wiring diagram, see SYSTEM WIRING DIAGRAMS

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1. Check unlock warning switch assy. Check the continuity between the connector terminals using (Scheme 105) and (Scheme 106). If the continuity is not as specified, replace the switch. OK: Go to next step. NG: Replace unlock warning switch assy.
2. Check wire harness (key unlock warning switch - ECM) Check the continuity between terminal 2 of the key unlock warning switch connector and terminal KSW (E6-23) of the ECM connector. Standard: Continuity OK: Check and replace ECM (See «HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS»(ref-174461-S15605692682005040500000) ). NG: Repair or replace harness and connector.

See also:
• CUSTOMER PROBLEM ANALYSIS CHECK
• PROBLEM SYMPTOMS TABLE