DTC B2799-86: Engine Immobilizer System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid [12/2019 - 10/2021]: Procedure

1. Register the ECU communication ID code.

   Refer to REGISTRATION [12/2019 - 10/2021]

   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 (Certification ECU (Smart Key ECU Assembly))	*b	Waveform
   *c	Approximately 160 ms.	*d	Approximately 270 ms.

   Measurement Condition

   Tester Connection	Condition	Tool Setting	Specified Condition
   A19-3 (EFII) - Body ground	Ignition switch ON	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 not output, or has abnormal wavelength or shape	C

Result: 

B 

See step  6

Result: 

C 

REPLACE ECM. Refer to  REMOVAL [12/2019 - 09/2020]  , or refer to  REMOVAL [09/2020 - 10/2022] 

Result: 

A 

See step  3

1. Using an oscilloscope, check the waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Measurement Condition

   Tester Connection	Condition	Tool Setting	Specified Condition
   A19-4 (EFIO) - Body ground	Ignition switch turned to ON using registered electrical key transmitter sub-assembly	2 V/DIV., 500 ms./DIV.	Pulse generation (See waveform)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [12/2019 - 11/2023] 

Result: 

OK 

See step  4

1. Register the ECU communication ID code.

   Refer to REGISTRATION [12/2019 - 10/2021]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

1. Using an electrical key transmitter sub-assembly which is registered to the vehicle, turn the ignition switch to ON.
2. 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 

END (ECU COMMUNICATION ID HAS NOT BEEN REGISTERED) 

Result: 

NG 

REPLACE ECM. Refer to  REMOVAL [12/2019 - 09/2020]  , or refer to  REMOVAL [09/2020 - 10/2022] 

1. Disconnect the A28 ECM connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A28-45 (IMO) - Body ground	Ignition switch turned to ON using registered electrical key transmitter sub-assembly	Terminal IMO stuck low (2.4 V or less)
   		Terminal IMO stuck high (12 V) or abnormal waveform

   Result

   Result	Proceed to
   Terminal IMO stuck low (2.4 V or less)	A
   Terminal IMO stuck high (12 V) or abnormal waveform	B

Result: 

B 

REPLACE ECM. Refer to  REMOVAL [12/2019 - 09/2020]  , or refer to  REMOVAL [09/2020 - 10/2022] 

Result: 

A 

See step  7

1. Disconnect the A19 certification ECU (smart key ECU assembly) connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A19-3 (EFII) - A28-45 (IMO)	Always	Below 1 Ω
   A19-3 (EFII) or A28-45 (IMO) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [12/2019 - 11/2023] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR