Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Immobilizer System does not Operate Properly [10/2021 - 10/2022]: Procedure
- CHECK FOR DTC
- Check for DTCs.
Body Electrical > Smart Key > Trouble Codes
Powertrain > Engine > Trouble Codes
Result
Result Proceed to DTCs are not output A DTCs are output B
Result:
B
GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2021 - 10/2022]
Result:
A
See step 2
- Check for DTCs.
- READ VALUE USING GTS (IMMOBILIZER FUEL CUT STATUS)
- Read the Data List according to the display on the GTS.
Powertrain > Engine > Data List
Tester Display Measurement Item Range Normal Condition Diagnostic Note Immobilizer Fuel Cut Status Status of immobilizer fuel cut OFF or ON - - Powertrain > Engine > Data List
Tester Display Immobilizer Fuel Cut Status OK
OFF is displayed after the engine is started.
Result
Proceed to OK NG
Result:
OK
GO TO SFI SYSTEM. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 10/2022]
Result:
NG
See step 3
- Read the Data List according to the display on the GTS.
- CHECK WHETHER ENGINE STARTS
- Check that the engine starts 5 seconds after the ignition switch turned to ON.
OK
Engine starts normally.
Result
Proceed to OK NG
Result:
OK
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ]
Result:
NG
See step 4
- Check that the engine starts 5 seconds after the ignition switch turned to ON.
- CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILIZER CODE ECU) - ECM)
- Disconnect the H53 ID code box (immobilizer code ECU) connector.
- Disconnect the A28 ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition H53-3 (EFII) - A28-45 (IMO) Always Below 1 Ω H53-4 (EFIO) - A28-59 (IMI) Always Below 1 Ω H53-3 (EFII) or A28-45 (IMO) - Other terminals and body ground Always 10 kΩ or higher H53-4 (EFIO) or A28-59 (IMI) - Other terminals and body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 5
- CHECK ECM (TERMINAL EFIO AND EFII)
- Connect the H53 ID code box (immobilizer code ECU) connector.
- Connect the A28 ECM connector.
- Using an oscilloscope, check the waveform.
*a Component with harness connected
(ID Code Box (Immobilizer Code ECU))*b Approximately 160 ms. *c Approximately 270 ms. *d Approximately 40 ms. *e Approximately 60 ms. *f Waveform (EFII) *g Waveform (EFIO) *h Waveform A *i Waveform B *j Waveform C *k Waveform A (detail) - - NOTE:The waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown.
OK
Tester Connection Condition Tool Setting Specified Condition H53-3 (EFII) - Body ground Within 3 seconds of engine start or within 3 seconds of ignition switch turned to ON after battery cable disconnected and reconnected 2 V/DIV., 500 ms./DIV. Pulse generation
(See waveform (EFII))H53-4 (EFIO) - Body ground Within 3 seconds of engine start or within 3 seconds of ignition switch turned to ON after battery cable disconnected and reconnected 2 V/DIV., 500 ms./DIV. Pulse generation
(See waveform (EFIO))Result
Result Proceed to Normal waveform A Waveform A or C not output, or has abnormal wavelength or shape B Waveform B not output, or has abnormal wavelength or shape C
Result:
B
REPLACE ID CODE BOX (IMMOBILIZER CODE ECU). Refer to REMOVAL [12/2019 - 10/2022]
Result:
C
REPLACE ECM. Refer to REMOVAL [09/2020 - 10/2022]
Result:
A
See step 6
- REGISTER ECU COMMUNICATION ID
- Register the ECU communication ID.
HINT:
Refer to Registration.
Refer to REGISTRATION [10/2021 - 10/2022]
Result
Proceed to NEXT
Result:
NEXT
See step 7
- Register the ECU communication ID.
- CHECK WHETHER ENGINE STARTS
Result:
OK
END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)
Result:
NG
REPLACE ID CODE BOX (IMMOBILIZER CODE ECU). Refer to REMOVAL [12/2019 - 10/2022]
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.