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.
DTC B2799-86: Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid [11/2018 - ]: Procedure
- REGISTER ECU COMMUNICATION ID (ID CODE BOX (IMMOBILISER CODE ECU) - HYBRID VEHICLE CONTROL ECU ASSEMBLY)
- Register the communication ID codes.
HINT:
Refer to the Registration.
Refer to REGISTRATION [11/2018 - 10/2019] , or refer to REGISTRATION [10/2019 - 12/2021] , or refer to REGISTRATION [12/2021 - ]
Result
Proceed to NEXT
Result:
NEXT
See step 2
- Register the communication ID codes.
- CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (TERMINAL IMO)
- Using an oscilloscope, check the waveform.
*a Component with harness connected
(Hybrid Vehicle Control ECU Assembly)*b Waveform *c Approximately 160 ms. *d Approximately 270 ms. Measurement Condition
Tester Connection Condition Tool Setting Specified Condition A30-23 (IMO) - 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
Result Proceed to Normal waveform A Terminal IMO stuck low (2.4 V or less) B Waveform length or shape is abnormal, or IMO terminal stuck at Hi (12 V) C
Result:
B
See step 6
Result:
C
REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY. Refer to REMOVAL [11/2018 - 02/2019] , or refer to REMOVAL [02/2019 - 10/2019] , or refer to REMOVAL [10/2019 - 08/2020] , or refer to REMOVAL [08/2020 - 12/2021] , or refer to REMOVAL [12/2021 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]
Result:
A
See step 3
- Using an oscilloscope, check the waveform.
- CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (TERMINAL IMI)
- Using an oscilloscope, check the waveform.
*a Component with harness connected
(Hybrid Vehicle Control ECU Assembly)*b Waveform *c Approximately 160 ms. *d Approximately 270 ms. Measurement Condition
Tester Connection Condition Tool Setting Specified Condition A30-10 (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 ID CODE BOX (IMMOBILISER CODE ECU). Refer to REMOVAL [11/2018 - 02/2019] , or refer to REMOVAL [02/2019 - 10/2019] , or refer to REMOVAL [10/2019 - 08/2020] , or refer to REMOVAL [08/2020 - 12/2021] , or refer to REMOVAL [12/2021 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]
Result:
OK
See step 4
- Using an oscilloscope, check the waveform.
- REGISTER ECU COMMUNICATION ID (ID CODE BOX (IMMOBILISER CODE ECU) - HYBRID VEHICLE CONTROL ECU ASSEMBLY)
- Register the ECU communication ID codes.
HINT:
Refer to the Registration.
Refer to REGISTRATION [11/2018 - 10/2019] , or refer to REGISTRATION [10/2019 - 12/2021] , or refer to REGISTRATION [12/2021 - ]
Result
Proceed to NEXT
Result:
NEXT
See step 5
- Register the ECU communication ID codes.
- CHECK WHETHER HYBRID CONTROL SYSTEM STARTS
- Check that the hybrid control system starts.
Result
Result Proceed to Hybrid control system was started A Hybrid control system was not started B
Result:
A
END (ECU COMMUNICATION ID HAS NOT BEEN REGISTERED)
Result:
B
REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY. Refer to REMOVAL [11/2018 - 02/2019] , or refer to REMOVAL [02/2019 - 10/2019] , or refer to REMOVAL [10/2019 - 08/2020] , or refer to REMOVAL [08/2020 - 12/2021] , or refer to REMOVAL [12/2021 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]
- Check that the hybrid control system starts.
- CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (TERMINAL IMO)
- Disconnect the A30 hybrid vehicle control ECU assembly connector.
*a Front view of wire harness connector
(to Hybrid Vehicle Control ECU Assembly) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition A30-23 (IMO) - Body ground Power switch turned on (IG) using registered electrical key transmitter sub-assembly Terminal IMO stuck low (2.4 V or less) Terminal IMO stuck high (12 V) Result
Result Proceed to Terminal IMO stuck low (2.4 V or less) A Terminal IMO stuck high (12 V) B
Result:
B
REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY. Refer to REMOVAL [11/2018 - 02/2019] , or refer to REMOVAL [02/2019 - 10/2019] , or refer to REMOVAL [10/2019 - 08/2020] , or refer to REMOVAL [08/2020 - 12/2021] , or refer to REMOVAL [12/2021 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]
Result:
A
See step 7
- Disconnect the A30 hybrid vehicle control ECU assembly connector.
- CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - HYBRID VEHICLE CONTROL ECU ASSEMBLY)
- Disconnect the G57 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 G57-3 (EFII) - A30-23 (IMO) Always Below 1 Ω G57-3 (EFII) or A30-23 (IMO) - Other terminals and body ground Always 10 kΩ or higher G57-4 (EFIO) - A30-10 (IMI) Always Below 1 Ω G57-4 (EFIO) or A30-10 (IMI) - Other terminals and body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE ID CODE BOX (IMMOBILISER CODE ECU). Refer to REMOVAL [11/2018 - 02/2019] , or refer to REMOVAL [02/2019 - 10/2019] , or refer to REMOVAL [10/2019 - 08/2020] , or refer to REMOVAL [08/2020 - 12/2021] , or refer to REMOVAL [12/2021 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.