DTC B2799-86: Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid [11/2018 - ]: Procedure

1. Reregister the ECU communication ID.

   Refer to REGISTRATION [11/2018 - 10/2022] , or refer to REGISTRATION [10/2022 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  2

1. Using an oscilloscope, check the waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Transponder Key ECU Assembly)	*b	Waveform
   *c	Approximately 160 ms.	*d	Approximately 270 ms.

   Measurement Condition

   Tester Connection	Condition	Tool Setting	Specified Condition
   G52-10 (EFII) - Body ground	Within 3 seconds of engine start or within 3 seconds of ignition switch turned ON after cable disconnected and reconnected to battery	2 V/DIV., 500 ms./DIV.	Pulse generation (See waveform)

   Result

   Result	Proceed to
   Normal waveform	A
   Terminal EFII stuck low (2.4 V or less)	B
   Waveform length or shape is abnormal, or EFII terminal stuck at Hi (12 V)	C

Result: 

B 

See step  6

Result: 

C 

REPLACE ECM. Refer to  REMOVAL [11/2018 - 08/2020]  , or refer to  REMOVAL [08/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

Result: 

A 

See step  3

1. Using an oscilloscope, check the waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Transponder Key ECU Assembly)	*b	Waveform
   *c	Approximately 160 ms.	*d	Approximately 270 ms.

   Measurement Condition

   Tester Connection	Condition	Tool Setting	Specified Condition
   G52-11 (EFIO) - Body ground	Within 3 seconds of engine start or within 3 seconds of ignition switch turned ON after cable disconnected and reconnected to battery	2 V/DIV., 500 ms./DIV.	Pulse generation (See waveform)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE TRANSPONDER KEY 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: 

OK 

See step  4

1. Reregister the ECU communication ID.

   Refer to REGISTRATION [11/2018 - 10/2022] , or refer to REGISTRATION [10/2022 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

1. Check that the engine starts.

   Result

   Result	Proceed to
   Engine was started	A
   Engine was not started	B

Result: 

A 

END (ECU COMMUNICATION ID HAS NOT BEEN REGISTERED) 

Result: 

B 

REPLACE ECM. Refer to  REMOVAL [11/2018 - 08/2020]  , or refer to  REMOVAL [08/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

1. Disconnect the ECM connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to ECM)

2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A24-25 (IMO) - Body ground	Ignition switch turned ON 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 ECM. Refer to  REMOVAL [11/2018 - 08/2020]  , or refer to  REMOVAL [08/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

Result: 

A 

See step  7

1. Disconnect the G52 transponder key ECU assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G52-10 (EFII) - A24-25 (IMO)	Always	Below 1 Ω
   G52-10 (EFII) or A24-25 (IMO) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE TRANSPONDER KEY 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: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR