ENGINE IMMOBILISER SYSTEM, Diagnostic DTC:B2799

DTC Code	DTC Name
B2799	Engine Immobiliser System Malfunction

DESCRIPTION

This DTC is output when one of the following occurs: 1) the ECM detected errors in its own communications with the immobiliser code ECU; 2) the ECM detects errors in the communication lines; or 3) the ECU communication ID between the immobiliser code ECU and ECM is different and an engine start is attempted. Before troubleshooting for this DTC, make sure no certification ECU DTCs are present. If present, troubleshoot the certification ECU DTCs first.

DTC Code	DTC Detection Condition	Trouble Area
B2799	Either condition is met (1 trip detection logic*1): Error in communication between ECM and immobiliser code ECU Error in communication lines Communication ID is different during communication with immobiliser code ECU	Harness or connector ID code box ECM Telephone transceiver assembly*2

DTC Code

DTC Detection Condition

Trouble Area

B2799

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

Error in communication between ECM and immobiliser code ECU
Error in communication lines
Communication ID is different during communication with immobiliser code ECU

Harness or connector
ID code box
ECM
Telephone transceiver assembly*2

*1: Only output while a malfunction is present.
*2: w/ Blocking System

WIRING DIAGRAM

INSPECTION PROCEDURE

Note

The fixed 12 V power source voltage in the ECM is output through a resistance from terminal IMI. The ID code box grounds or does not ground this power source voltage accordingly.
The fixed 12 V power source voltage in the ID code box is output through a resistance from terminal EFII. The ECM grounds or does not ground this power source voltage accordingly.
When replacing the ID code box, ECM or telephone transceiver assembly (w/ Blocking System), refer to the Service Bulletin.
After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

Tech Tips

w/ Blocking System:

When DTC B1587 and B2799 are output simultaneously, perform troubleshooting for DTC B2799 first.
After troubleshooting for this DTC, make sure B2799 is not output. If output, troubleshoot the blocking system DTCs next.

PROCEDURE

CLEAR DTC
1. Clear the DTCs Click here.
NEXT

CHECK FOR DTC

Check for DTCs Click here.

OK
DTC B2799 is not output.

Result
Result	Proceed to
OK	A
NG (w/ Blocking System)	B
NG (w/o Blocking System)	C

CHECK BLOCKING SYSTEM Click here

REREGISTER ECU COMMUNICATION ID Click here

USE SIMULATION METHOD TO CHECK Click here

CHECK BLOCKING SYSTEM

Check the blocking system setting.

Tech Tips

Check with the customer's contacted service provider to determine whether the blocking system is set.
Request that the customer have the service provider unset the blocking system.

Result
Result	Proceed to
Blocking system is unset.	A
Blocking system is set.	B

UNSET BLOCKING SYSTEM

REREGISTER ECU COMMUNICATION ID
1. Reregister the ECU - ECM communication ID (Refer to Service Bulletin).
NEXT
CLEAR DTC
1. Clear the DTCs Click here.
NEXT
CHECK FOR DTC
1. Check for DTCs Click here.
  
  OK
  
  DTC B2799 is not output.
NG
CHECK CONNECTION OF CONNECTOR Click here

OK

END (ECU COMMUNICATION ID IS NOT REGISTERED CORRECTLY)
CHECK CONNECTION OF CONNECTOR
1. Turn the engine switch off.
2. Check that the connectors are properly connected to the ECM and ID code box.
  
  OK
  
  Connectors are properly connected.
NG
CONNECT CONNECTOR CORRECTLY

OK

OK
Connectors are properly connected.

CHECK HARNESS AND CONNECTOR (SFI COMMUNICATION LINE)

Disconnect the L32 ID code box connector.
Disconnect the A13 ECM connector.
w/ Blocking System:
1. Disconnect the L180 telephone transceiver assembly connector.

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

Standard Resistance

w/o Blocking System

Tester Connection	Condition	Specified Condition
L32-6 (EFIO) - A13-31 (IMI)	Always	Below 1 Ω
L32-5 (EFII) - A13-30 (IMO)	Always	Below 1 Ω
L32-6 (EFIO) - Body ground	Always	10 kΩ or higher
L32-5 (EFII) - Body ground	Always	10 kΩ or higher

w/ Blocking System

Tester Connection	Condition	Specified Condition
L32-6 (EFIO) - L180-2 (BLK4)	Always	Below 1 Ω
L32-5 (EFII) - L180-1 (BLK1)	Always	Below 1 Ω
L180-8 (BLK3) - A13-31 (IMI)	Always	Below 1 Ω
L180-7 (BLK2) - A13-30 (IMO)	Always	Below 1 Ω
L32-6 (EFIO) - Body ground	Always	10 kΩ or higher
L32-5 (EFII) - Body ground	Always	10 kΩ or higher
A13-30 (IMO) - Body ground	Always	10 kΩ or higher
A13-31 (IMI) - Body ground	Always	10 kΩ or higher

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

Standard Voltage

w/o Blocking System

Tester Connection	Condition	Specified Condition
L32-6 (EFIO) - Body ground	Always	Below 1 V
L32-5 (EFII) - Body ground	Always	Below 1 V

w/ Blocking System

Tester Connection	Condition	Specified Condition
L32-6 (EFIO) - Body ground	Always	Below 1 V
L32-5 (EFII) - Body ground	Always	Below 1 V
A13-30 (IMO) - Body ground	Always	Below 1 V
A13-31 (IMI) - Body ground	Always	Below 1 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE ECM
1. Temporarily replace the ECM with a new one.
  - for 1UR-FSE: Click here
  - for 1UR-FE: Click here
NEXT
REREGISTER ECU COMMUNICATION ID
1. Reregister the ECU - ECM communication ID (Refer to Service Bulletin).
NEXT
CLEAR DTC
1. Clear the DTCs Click here.
NEXT

CHECK FOR DTC

Check for DTCs Click here.

OK
DTC B2799 is not output.

Result
Result	Proceed to
OK	A
NG (w/o Blocking System)	B
NG (w/ Blocking System)	C

REPLACE ID CODE BOX

REPLACE ID CODE BOX Click here

END (ECM IS DEFECTIVE)

REPLACE ID CODE BOX
1. Temporarily replace the ID code box with a new one (Refer to Service Bulletin).
NEXT
REGISTER ECU COMMUNICATION ID
1. Reregister the ECU - ECM communication ID (Refer to Service Bulletin).
NEXT
CLEAR DTC
1. Clear the DTCs Click here.
NEXT
CHECK FOR DTC
1. Check for DTCs Click here.
  
  OK
  
  DTC B2799 is not output.
NG
REPLACE TELEPHONE TRANSCEIVER ASSEMBLY

OK

END (ID CODE BOX IS DEFECTIVE)