ENGINE IMMOBILISER SYSTEM (w/ Smart Entry and Start System), Diagnostic DTC:B2799

DTC Code	DTC Name
B2799	Engine Immobiliser System Malfunction

DESCRIPTION

w/o Wireless Door Lock Buzzer Answer Back Function:

When there are communication malfunctions between the ECM and ID code box (immobiliser code ECU), or when the communication ID codes do not match, the ECM stores this DTC.
w/o Wireless Door Lock Buzzer Answer Back Function:

When there are communication malfunctions between the ECM and certification ECU (smart key ECU assembly), or when the communication ID codes do not match, the ECM stores this DTC.

DTC Code	DTC Detection Condition	Trouble Area	DTC Output Confirmation Operation
B2799	Either condition is met (1 trip detection logic4): A malfunction in the communication or communication lines between the ECM and ID code box (immobiliser code ECU)1 or certification ECU (smart key ECU assembly)2. A matching communication code cannot be verified during communication between the ECM and ID code box (immobiliser code ECU)1 or certification ECU (smart key ECU assembly)*2.	ID code box (immobiliser code ECU)1 Certification ECU (smart key ECU assembly)2 ECM Telephone transceiver assembly*3 Wire harness or connector	Either condition is met: Within 10 seconds of an engine start operation being performed (with the shift lever in P and the brake pedal depressed, the engine switch is pressed while carrying the key). If there is a malfunction, the engine stops (communication begins within 3 seconds of the engine start operation being performed, and DTCs are stored after 6 seconds). 10 seconds after the engine switch is turned on (IG) after reconnecting the cable to the negative (-) battery terminal (communication begins within 3 seconds of the engine switch being turned on (IG), and DTCs are stored after 6 seconds).

DTC Code

DTC Detection Condition

Trouble Area

DTC Output Confirmation Operation

B2799

Either condition is met (1 trip detection logic*4):

A malfunction in the communication or communication lines between the ECM and ID code box (immobiliser code ECU)*1 or certification ECU (smart key ECU assembly)*2.
A matching communication code cannot be verified during communication between the ECM and ID code box (immobiliser code ECU)*1 or certification ECU (smart key ECU assembly)*2.

ID code box (immobiliser code ECU)*1
Certification ECU (smart key ECU assembly)*2
ECM
Telephone transceiver assembly*3
Wire harness or connector

Either condition is met:

Within 10 seconds of an engine start operation being performed (with the shift lever in P and the brake pedal depressed, the engine switch is pressed while carrying the key). If there is a malfunction, the engine stops (communication begins within 3 seconds of the engine start operation being performed, and DTCs are stored after 6 seconds).
10 seconds after the engine switch is turned on (IG) after reconnecting the cable to the negative (-) battery terminal (communication begins within 3 seconds of the engine switch being turned on (IG), and DTCs are stored after 6 seconds).

*1: w/o Wireless Door Lock Buzzer Answer Back Function
*2: w/ Wireless Door Lock Buzzer Answer Back Function
*3: w/ Blocking System
*4: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected	Fail-safe Operation when Malfunction Detected
Engine cannot be started	-

Related Data List and Active Test
DTC Code	Data List and Active Test
B2799	-

WIRING DIAGRAM

w/o Blocking System
w/ Blocking System

INSPECTION PROCEDURE

Note

When replacing the certification ECU (smart key ECU assembly)*1, ID code box (immobiliser code ECU)*2 or telephone transceiver assembly*3, refer to Service Bulletin.
After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.
When the telephone transceiver assembly is replaced, it is necessary to set the contract mode.*

*1: w/ Blocking System and Wireless Door Lock Buzzer Answer Back Function
*2: w/o Wireless Door Lock Buzzer Answer Back Function
*3: w/ Blocking System

Tech Tips

When DTC B2799 and the certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.

PROCEDURE

REGISTER ECU COMMUNICATION ID
1. Register the ECU communication ID.
  
  Tech Tips
  
  Refer to Service Bulletin.
NEXT
CLEAR DTC
1. Clear the DTCs Click here.
NEXT

CHECK FOR DTC

Start the engine.
Perform "DTC Output Confirmation Operation" procedure.

Check for DTCs Click here.

OK
DTC B2799 is not output.

Result

Result	Proceed to
OK	A
NG (DTC B2799 is output) (w/ Blocking System)	B
NG (DTC B2799 is output) (w/o Blocking System and w/ Wireless Door Lock Buzzer Answer Back Function)	C
NG (DTC B2799 is output) (w/o Blocking System and Wireless Door Lock Buzzer Answer Back Function)	D
NG (Other DTCs are output)	E

CHECK HARNESS AND CONNECTOR (ECM - TELEPHONE TRANSCEIVER ASSEMBLY) Click here

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ECM) Click here

GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

CHECK HARNESS AND CONNECTOR (ECM - TELEPHONE TRANSCEIVER ASSEMBLY)

Disconnect the A25 ECM connector.
Disconnect the I70 telephone transceiver assembly connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A25-30 (IMO) - I70-7 (BLK2)	Always	Below 1 Ω
A25-30 (IMO) or I70-7 (BLK2) - Body ground	Always	10 kΩ or higher
A25-31 (IMI) - I70-8 (BLK3)	Always	Below 1 Ω
A25-31 (IMI) or I70-8 (BLK3) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (TELEPHONE TRANSCEIVER ASSEMBLY - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

Disconnect the A43 certification ECU (smart key ECU assembly) connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
I70-1 (BLK1) - A43-14 (EFII)	Always	Below 1 Ω
I70-1 (BLK1) or A43-14 (EFII) - Body ground	Always	10 kΩ or higher
I70-2 (BLK4) - A43-13 (EFIO)	Always	Below 1 Ω
I70-2 (BLK4) or A43-13 (EFIO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE TELEPHONE TRANSCEIVER ASSEMBLY
1. Temporarily replace the telephone transceiver assembly with a new or known good one.
  
  Tech Tips
  
  Refer to Service Bulletin.
NEXT
REGISTER ECU COMMUNICATION ID
1. Register the ECU communication ID.
  
  Tech Tips
  
  Refer to Service Bulletin.
NEXT
CLEAR DTC
1. Clear the DTCs Click here.
NEXT
CHECK FOR DTC
1. Perform "DTC Output Confirmation Operation" procedure.
2. Check for DTCs Click here.
  
  OK
  
  DTC B2799 is not output.
NG
INSPECT CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (TERMINAL EFII) Click here

OK

END (TELEPHONE TRANSCEIVER ASSEMBLY WAS DEFECTIVE)

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ECM)

Disconnect the A43 certification ECU (smart key ECU assembly) connector.
Disconnect the A25 ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A43-14 (EFII) - A25-29 (IMO)	Always	Below 1 Ω
A43-14 (EFII) or A25-29 (IMO) - Body ground	Always	10 kΩ or higher
A43-13 (EFIO) - A25-28 (IMI)	Always	Below 1 Ω
A43-13 (EFIO) or A25-28 (IMI) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

INSPECT CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (TERMINAL EFII)

Using an oscilloscope, check the waveform.

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

Measurement Condition

Tester Connection

Condition

Tool Setting

Specified Condition

A43-14 (EFII) - Body ground

Within 3 seconds of engine start or within 3 seconds of engine switch turned on (IG) after battery cable disconnected and reconnected

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

OK
The waveform is similar to that shown in the illustration.

Result

Result	Proceed to
Normal waveform	A
Terminal IMO stuck low (2.4 V or less)	B
Terminal IMO stuck high (12 V), or has abnormal wavelength or shape	C

INSPECT ECM (IMO TERMINAL VOLTAGE) Click here

REPLACE ECM Click here

INSPECT CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (TERMINAL EFIO)

Using an oscilloscope, check the waveform.

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

Measurement Condition

Tester Connection

Condition

Tool Setting

Specified Condition

A43-13 (EFIO) - Body ground

Engine switch on (IG) using registered electrical key transmitter sub-assembly

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

OK
The waveform is similar to that shown in the illustration.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REGISTER ECU COMMUNICATION ID
1. Register the ECU communication ID.
  
  Tech Tips
  
  Refer to Service Bulletin.
NEXT
CHECK WHETHER ENGINE STARTS
1. Using an electrical key transmitter sub-assembly which is registered to the vehicle, turn the engine switch on (IG).
2. Check that the engine starts 5 seconds after the engine switch was turned on (IG).
  
  OK
  
  Engine starts normally.
NG
REPLACE ECM Click here

OK

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

OK
Engine starts normally.

INSPECT ECM (IMO TERMINAL VOLTAGE)

Text in Illustration

*a
Front view of wire harness connector

(to ECM)

Disconnect the A25 ECM connector.
Turn the engine switch on (IG).

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

Standard Voltage

Tester Connection	Condition	Specified Condition
A25-29 (IMO) - Body ground	Engine switch on (IG) using registered electrical key transmitter sub-assembly	Terminal IMO stuck low (2.4 V or less)
A25-29 (IMO) - Body ground		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

REPLACE ECM Click here

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
1. Replace the certification ECU (smart key ECU assembly) with a new one.
  
  Tech Tips
  
  Refer to Service Bulletin.
NEXT
REGISTER ECU COMMUNICATION ID
1. Register the ECU communication ID.
  
  Tech Tips
  
  Refer to Service Bulletin.
NEXT
CHECK WHETHER ENGINE STARTS
1. Using an electrical key transmitter sub-assembly which is registered to the vehicle, turn the engine switch on (IG).
2. Check that the engine starts 5 seconds after the engine switch was turned on (IG).
  
  OK
  
  Engine starts normally.
NG
REPLACE ECM Click here

OK

END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)
REGISTER ECU COMMUNICATION ID

Register the ECU communication ID.

Tech Tips

Refer to Service Bulletin.

NEXT
CLEAR DTC
1. Clear the DTCs Click here.
NEXT
CHECK FOR DTC
1. Perform "DTC Output Confirmation Operation" procedure.
2. Check for DTCs Click here.
  
  OK
  
  DTC B2799 is not output.
NG
CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - ECM) Click here

OK

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - ECM)

Disconnect the I20 ID code box (immobiliser code ECU) connector.
Disconnect the A25 ECM connector.

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

Standard Resistance

for 2GR-FE
Tester Connection	Condition	Specified Condition
I20-3 (EFII) - A25-30 (IMO)	Always	Below 1 Ω
I20-3 (EFII) or A25-30 (IMO) - Body ground	Always	10 kΩ or higher
I20-4 (EFIO) - A25-31 (IMI)	Always	Below 1 Ω
I20-4 (EFIO) or A25-31 (IMI) - Body ground	Always	10 kΩ or higher

for 2AR-FE
Tester Connection	Condition	Specified Condition
I20-3 (EFII) - A25-29 (IMO)	Always	Below 1 Ω
I20-3 (EFII) or A25-29 (IMO) - Body ground	Always	10 kΩ or higher
I20-4 (EFIO) - A25-28 (IMI)	Always	Below 1 Ω
I20-4 (EFIO) or A25-28 (IMI) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE ECM
1. Temporarily replace the ECM with a new one Click here for 2GR-FE , Click here for 2AR-FE).
NEXT
CLEAR DTC
1. Clear the DTCs Click here.
NEXT
CHECK FOR DTC
1. Perform "DTC Output Confirmation Operation" procedure.
2. Check for DTCs Click here.
  
  OK
  
  DTC B2799 is not output.
NG
REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

OK

END (ECM WAS DEFECTIVE)