DTC B2799-86: Engine Immobilizer System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid [10/2021 - 10/2022]: Procedure

1. Register the ECU communication ID code.

   Refer to REGISTRATION [10/2021 - 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 (ID Code Box (Immobilizer Code ECU))	*b	Waveform
   *c	Approximately 160 ms.	*d	Approximately 270 ms.

   OK

   Tester Connection	Condition	Tool Setting	Specified Condition
   H53-3 (EFII) - Body ground	Ignition switch ON	2 V/DIV., 500 ms./DIV.	Pulse generation (See waveform)

   Result

   Result	Proceed to
   Normal waveform	A
   Terminal IMO 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 [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 (ID Code Box (Immobilizer Code ECU))	*b	Waveform
   *c	Approximately 160 ms.	*d	Approximately 270 ms.

   Measurement Condition

   Tester Connection	Condition	Tool Setting	Specified Condition
   H53-4 (EFIO) - Body ground	Within 3 seconds of engine start or within 3 seconds of ignition switch turned to ON 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 (IMMOBILIZER CODE ECU). Refer to  REMOVAL [12/2019 - 10/2022] 

Result: 

OK 

See step  4

1. Register the ECU communication ID code.

   Refer to REGISTRATION [10/2021 - 10/2022]

   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 [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 [09/2020 - 10/2022] 

Result: 

A 

See step  7

1. Disconnect the H53 ID code box (immobilizer code ECU) connector.
2. 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
   H53-3 (EFII) or A28-45 (IMO) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ID CODE BOX (IMMOBILIZER CODE ECU). Refer to  REMOVAL [12/2019 - 10/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR