DTC B279A-12: Engine Immobiliser System Circuit Short to Battery [06/2018 - ]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus ES 300h, 2023 Lexus ES 300h, 2022 Lexus ES 300h, 2021 Lexus ES 300h, and 2020 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK CONNECTION OF CONNECTOR
- Turn the power switch off.
- Check that the connectors are properly connected to the hybrid vehicle control ECU and ID code box (immobiliser code ECU).
OK
Connectors are properly connected.
Result
Proceed to OK NG
Result:
NG
CONNECT CONNECTORS PROPERLY
Result:
OK
See step 2
- CHECK WHETHER HYBRID CONTROL SYSTEM STARTS
- Check that the hybrid control system starts.
OK
Hybrid control system starts normally.
Result
Proceed to OK NG
Result:
OK
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [06/2018 - ]
Result:
NG
See step 3
- Check that the hybrid control system starts.
- CHECK HYBRID VEHICLE CONTROL ECU (TERMINAL IMI)
- Using an oscilloscope, check the waveform.
*a Component with harness connected
(Hybrid Vehicle Control ECU)*b Waveform *c Approximately 160 ms. *d Approximately 270 ms. OK
Tester Connection Condition Tool Setting Specified Condition G60-22 (IMI) - Body ground Within 3 seconds of hybrid control system start or within 3 seconds of power switch turned on (IG) after cable disconnected and reconnected to auxiliary battery 2 V/DIV., 500 ms./DIV. Pulse generation
(See waveform)Result
Proceed to OK NG
Result:
NG
REPLACE HYBRID VEHICLE CONTROL ECU. Refer to REMOVAL [06/2018 - 08/2021] , or refer to REMOVAL [08/2021 - 09/2022] , or refer to REMOVAL [09/2022 - ]
Result:
OK
See step 4
- Using an oscilloscope, check the waveform.
- CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - HYBRID VEHICLE CONTROL ECU)
- Disconnect the G60 hybrid vehicle control ECU connector.
- Disconnect the G52 ID code box (immobiliser code ECU) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition G52-4 (EFIO) - G60-22 (IMI) Always Below 1 Ω Result
Proceed to OK NG
Result:
OK
REPLACE ID CODE BOX (IMMOBILISER CODE ECU). Refer to REMOVAL [06/2018 - 08/2021] , or refer to REMOVAL [08/2021 - 09/2022] , or refer to REMOVAL [09/2022 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR