DTC B2799-86: Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid [12/2024 - ]: Procedure

1. Register the ECU communication ID code.

   Refer to REGISTRATION [12/2024 - ]

   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 (Immobiliser Code ECU))	*b	Waveform
   *c	Approximately 160 ms.	*d	Approximately 270 ms.

   OK

   Tester Connection	Condition	Tool Setting	Specified Condition
   K65-3 (EFII) - Body ground	Within 3 seconds of hybrid control system 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

   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, or terminal EFII stuck high (12 V)	C

Result: 

B 

See step  7

Result: 

C 

See step  9

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 (Immobiliser Code ECU))	*b	Waveform
   *c	Approximately 160 ms.	*d	Approximately 270 ms.

   Measurement Condition

   Tester Connection	Condition	Tool Setting	Specified Condition
   K65-4 (EFIO) - Body ground	Within 3 seconds of hybrid control system 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 

See step  6

Result: 

OK 

See step  4

1. Register the ECU communication ID codes.

   Refer to REGISTRATION [12/2024 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

Pre-procedure1

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

• Check that the hybrid control system starts 5 seconds after the ignition switch turned to ON.

  OK

  Hybrid control system starts normally.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

END (ECU COMMUNICATION ID HAS NOT BEEN REGISTERED) 

Result: 

NG 

REPLACE ECM 

Refer to REMOVAL [12/2024 - ]

Pre-procedure1

• Disconnect the K65 ID code box (immobiliser code ECU) connector.
• Disconnect the A3 ECM connector

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition
  K65-4 (EFIO) - A3-55 (IMI)	Always	Below 1 Ω
  K65-4 (EFIO) or A3-55 (IMI) - Other terminals and body ground	Always	10 kΩ or higher

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

REPLACE ID CODE BOX (IMMOBILISER CODE ECU) 

Refer to REMOVAL [12/2024 - ]

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Pre-procedure1

• Disconnect the A3 ECM connector

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

  Standard Voltage

  Tester Connection	Condition	Specified Condition
  A3-54 (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

Post-procedure1

• None

Result: 

B 

REPLACE ECM 

Refer to REMOVAL [12/2024 - ]

Result: 

A 

See step  8

Pre-procedure1

• Disconnect the K65 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
  K65-3 (EFII) - A3-54 (IMO)	Always	Below 1 Ω
  K65-3 (EFII) or A3-54 (IMO) - Other terminals and body ground	Always	10 kΩ or higher
  K65-4 (EFIO) - A3-55 (IMI)	Always	Below 1 Ω
  K65-4 (EFIO) or A3-55 (IMI) - Other terminals and body ground	Always	10 kΩ or higher

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

REPLACE ID CODE BOX (IMMOBILISER CODE ECU) 

Refer to REMOVAL [12/2024 - ]

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Pre-procedure1

• Disconnect the K65 ID code box (immobiliser code ECU) connector.
• Disconnect the A3 ECM connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition
  K65-3 (EFII) - A3-54 (IMO)	Always	Below 1 Ω
  K65-3 (EFII) or A3-54 (IMO) - Other terminals and body ground	Always	10 kΩ or higher

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

REPLACE ECM 

Refer to REMOVAL [12/2024 - ]

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR