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

DTC Code	DTC Name
B2799	Engine Immobiliser System Malfunction

DESCRIPTION

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

DTC Code	DTC Detection Condition	Trouble Area	DTC Output Confirmation Operation
B2799	Either condition is met (1 trip detection logic*): A malfunction occurs in the communication or communication lines between the ECM and transponder key ECU assembly. A communication code cannot be verified during communication between the ECM and transponder key ECU assembly.	Harness or connector Transponder key ECU assembly ECM	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, turn the ignition switch to ON). 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 ignition switch is turned to ON after reconnecting the cable to the negative (-) battery terminal (communication begins within 3 seconds of the ignition switch being turned to ON, 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*):

A malfunction occurs in the communication or communication lines between the ECM and transponder key ECU assembly.
A communication code cannot be verified during communication between the ECM and transponder key ECU assembly.

Harness or connector
Transponder key ECU assembly
ECM

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, turn the ignition switch to ON). 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 ignition switch is turned to ON after reconnecting the cable to the negative (-) battery terminal (communication begins within 3 seconds of the ignition switch being turned to ON, and DTCs are stored after 6 seconds).

*: 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

CAUTION / NOTICE / HINT

Note

When replacing the transponder key ECU assembly, refer to the Service Bulletin.
When replacing the ECM, refer to the INITIALIZATION Click here.
After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

PROCEDURE

CLEAR DTC
1. Clear the DTCs Click here.
NEXT

CHECK FOR DTC

Start the engine.
Wait 10 seconds or more.

Check for DTCs Click here.

Tech Tips

Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

OK
DTC B2799 is not output.

Result
Result	Proceed to
OK	A
NG (DTC B2799 is output)	B
NG (Other DTCs are output)	C

USE SIMULATION METHOD TO CHECK Click here

GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

INSPECT ECM (TERMINAL IMO)

Using an oscilloscope, check the waveform.

Text in Illustration
*A	for 1KR-FE	*B	for 1NR-FE
*C	for 1ND-TV	-	-
*a	Component with harness connected (ECM)	*b	Waveform

Measurement Condition
Item	Content
Tester Connection	A71-6 (IMO) - Body ground1 A58-29 (IMO) - Body ground2 A59-78 (IMO) - Body ground*3
Tool Setting	2 V/DIV., 500 ms./DIV.
Condition	Key inserted and cylinder turned from OFF to START

*1: for 1KR-FE

*2: for 1NR-FE

*3: for 1ND-TV

Tech Tips

The waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown.

OK
Waveform is output normally (refer to 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 Abnormal waveform	C

INSPECT ECM (IMO TERMINAL VOLTAGE) Click here

REPLACE ECM Click here

INSPECT ECM (TERMINAL IMI)

Using an oscilloscope, check the waveform.

Text in Illustration
*A	for 1KR-FE	*B	for 1NR-FE
*C	for 1ND-TV	-	-
*a	Component with harness connected (ECM)	*b	Waveform

Measurement Condition
Item	Content
Tester Connection	A71-39 (IMI) - Body ground1 A58-28 (IMI) - Body ground2 A59-77 (IMI) - Body ground*3
Tool Setting	2 V/DIV., 500 ms./DIV.
Condition	Ignition switch ON with an already registered vehicle key

*1: for 1KR-FE

*2: for 1NR-FE

*3: for 1ND-TV

Tech Tips

The waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown.

OK
Waveform is output normally (refer to illustration).

Result
Result	Proceed to
Normal waveform	A
Not output waveform or abnormal waveform	B

REPLACE TRANSPONDER KEY ECU ASSEMBLY Click here

REGISTER ECU COMMUNICATION ID
1. Reregister the ECU communication ID (Refer to Service Bulletin).
NEXT
CHECK WHETHER ENGINE STARTS
1. Check that the engine starts with an already registered vehicle key.
  
  OK
  
  Engine starts normally.
OK
END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

NG
REPLACE ECM Click here

INSPECT ECM (IMO TERMINAL VOLTAGE)

Disconnect the A71*1, A58*2 or A59 ECM connector.

*1: for 1KR-FE

*2: for 1NR-FE

*3: for 1ND-TV
Turn the ignition switch to ON.

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

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

Text in Illustration
*A	for 1KR-FE
*B	for 1NR-FE
*C	for 1ND-TV
*a	Front view of wire harness connector (to ECM)

REPLACE ECM Click here

CHECK HARNESS AND CONNECTOR (ECM - TRANSPONDER KEY ECU AND BODY GROUND)

Disconnect the F54 transponder key ECU assembly connector.
Disconnect the A71*1, A58*2 or A59*3 ECM connector.

*1: for 1KR-FE

*2: for 1NR-FE

*3: for 1ND-TV

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

Standard Resistance

for 1KR-FE
Tester Connection	Condition	Specified Condition
F54-12 (EFII) - A71-6 (IMO)	Always	Below 1 Ω
F54-12 (EFII) - Body ground	Always	10 kΩ or higher

for 1NR-FE
Tester Connection	Condition	Specified Condition
F54-12 (EFII) - A58-29 (IMO)	Always	Below 1 Ω
F54-12 (EFII) - Body ground	Always	10 kΩ or higher

for 1ND-TV
Tester Connection	Condition	Specified Condition
F54-12 (EFII) - A59-78 (IMO)	Always	Below 1 Ω
F54-12 (EFII) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE TRANSPONDER KEY ECU ASSEMBLY
1. Replace the transponder key ECU assembly (Refer to Service Bulletin).
NEXT
REGISTER KEY
1. Reregister the key (Refer to Service Bulletin).
NEXT
REGISTER ECU COMMUNICATION ID
1. Reregister the ECU communication ID (Refer to Service Bulletin).
NEXT

CHECK WHETHER ENGINE STARTS

Check that the engine starts with an already registered vehicle key.

OK
Engine starts normally.

Result
Result	Proceed to
OK	A
NG (for 1KR-FE)	B
NG (for 1NR-FE)	C
NG (for 1ND-TV)	D

END (TRANSPONDER KEY ECU WAS DEFECTIVE)

REPLACE ECM Click here

REPLACE ECM
1. Temporarily replace the ECM with a new one.
  Tech Tips
  - for 1KR-FE Click here.
  - for 1NR-FE Click here.
  - for 1ND-TV Click here.
NEXT
REGISTER ECU COMMUNICATION ID
1. Reregister the ECU communication ID (Refer to Service Bulletin).
NEXT
CHECK WHETHER ENGINE STARTS
1. Check that the engine starts with the key.
  
  OK
  
  Engine starts normally.
OK
END (ECM WAS DEFECTIVE)

NG
REPLACE TRANSPONDER KEY ECU ASSEMBLY