Toyota Tundra Service Manual: Engine Immobiliser System Malfunction (B2799)

Toyota Tundra Service Manual / Vehicle Interior / Engine Immobiliser / Engine Immobiliser System (w/o Smart Key System) / Engine Immobiliser System Malfunction (B2799)

DESCRIPTION

The ECM stores this DTC when a communication line between the ECM and transponder key ECU assembly is malfunctioning or the communication ID of the ECM and transponder key ECU assembly do not match.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

B2799

Engine Immobiliser System Malfunction

One of the following conditions is met:

  • Error in communication between ECM and transponder key ECU assembly.
  • Error in communication lines.
  • Communication ID is different during communication between ECM and transponder key ECU assembly.
  • Harness or connector
  • Transponder key ECU assembly
  • ECM
DTC Output Confirmation Operation:
  • Start the engine and wait 10 seconds.
  • After disconnecting and reconnecting the cable to the negative (-) battery terminal, turn the ignition switch to ON and wait 10 seconds.
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 No.

Data List and Active Test

B2799

-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • If the transponder key ECU assembly or ECM is replaced, refer to Registration.

    Click here

  • After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

HINT:

If transponder key ECU assembly DTCs are output simultaneously, troubleshoot the transponder key ECU assembly DTCs first.

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Click here

NEXT

2.

CHECK FOR DTC

(a) Start the engine.

(b) Check for DTCs.

Click here

HINT:

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

OK:

DTC B2799 is not output.

Result

Proceed to

OK

A

NG (B2799 is output)

B

NG (Other DTCs are output)

C
A

USE SIMULATION METHOD TO CHECK

C

GO TO DIAGNOSTIC TROUBLE CODE CHART

B

3.

CHECK TRANSPONDER KEY ECU ASSEMBLY (TERMINAL EFII)

(a) Using an oscilloscope, check the waveform.

*a

Component with harness connected

(Transponder Key ECU Assembly)

*b

Waveform

Measurement Condition:

Item

Content

Tester Connection

J26-12 (EFII) - Body ground

Tool Setting

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

Condition

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

OK:

Waveform is similar to that shown in the illustration.

Result

Proceed to

OK

A

NG (Terminal EFII stuck low (2.4 V or less))

B

NG (Terminal EFII stuck high (12 V) or abnormal waveform)

C
B

GO TO STEP 10

C

GO TO STEP 16

A

4.

CHECK TRANSPONDER KEY ECU ASSEMBLY (TERMINAL EFIO)

(a) Using an oscilloscope, check the waveform.

*a

Component with harness connected

(Transponder Key ECU Assembly)

*b

Waveform

Measurement Condition:

Item

Content

Tester Connection

J26-13 (EFIO) - Body ground

Tool Setting

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

Condition

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

OK:

Waveform is similar to that shown in the illustration.

NG

GO TO STEP 12

OK

5.

REGISTER ECU COMMUNICATION ID

(a) Reregister the ECU communication ID.

Click here

NEXT

6.

CHECK WHETHER ENGINE STARTS

(a) Using a registered key, turn the ignition switch to ON.

(b) Check that the engine starts 5 seconds after the ignition switch was turned to ON.

OK:

Engine starts normally.

OK

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)
NG

7.

REPLACE ECM

(a) Temporarily replace the ECM with a new one.

  • for 1UR-FE:

    Click here

  • for 3UR-FE:

    Click here

  • for 3UR-FBE:

    Click here

NEXT

8.

REGISTER ECU COMMUNICATION ID

(a) Reregister the ECU communication ID.

Click here

NEXT

9.

CHECK WHETHER ENGINE STARTS

(a) Using a registered key, turn the ignition switch to ON.

(b) Check that the engine starts 5 seconds after the ignition switch was turned to ON.

OK:

Engine starts normally.

OK

END (ECM WAS DEFECTIVE)
NG

REPLACE TRANSPONDER KEY ECU ASSEMBLY

10.

CHECK ECM (IMO TERMINAL VOLTAGE)

(a) Disconnect the ECM connector.

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Condition

Result

A24-29 (IMO) - Body ground*1

A24-48 (IMO) - Body ground*2

Ignition switch turned to ON using registered key

Terminal IMO stuck low (2.4 V or less)

Terminal IMO stuck high (12 V)
  • *1: for 1UR-FE
  • *2: for 3UR-FE, 3UR-FBE

*A

for 1UR-FE

*B

for 3UR-FE, 3UR-FBE

*a

Front view of wire harness connector

(to ECM)

Result

Proceed to

Terminal IMO stuck low (2.4 V or less)

A

Terminal IMO stuck high (12 V) or abnormal waveform

B
B

GO TO STEP 7

A

11.

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

(a) Disconnect the J26 transponder key ECU assembly connector.

(b) Disconnect the A24 ECM connector.

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

Standard Resistance:

for 1UR-FE

Tester Connection

Condition

Specified Condition

J26-12 (EFII) - A24-29 (IMO)

Always

Below 1 Ω

A24-29 (IMO) - Body ground

Always

10 kΩ or higher

J26-12 (EFII) - Body ground

Always

10 kΩ or higher
for 3UR-FE, 3UR-FBE

Tester Connection

Condition

Specified Condition

J26-12 (EFII) - A24-48 (IMO)

Always

Below 1 Ω

A24-48 (IMO) - Body ground

Always

10 kΩ or higher

J26-12 (EFII) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

12.

REPLACE TRANSPONDER KEY ECU ASSEMBLY

(a) Replace the transponder key ECU assembly with a new one.

Click here

NEXT

13.

REGISTER KEY

(a) Register the key.

Click here

NEXT

14.

REGISTER ECU COMMUNICATION ID

(a) Register the ECU communication ID.

Click here

NEXT

15.

CHECK WHETHER ENGINE STARTS

(a) Using a registered key, turn the ignition switch to ON.

(b) Check that the engine starts 5 seconds after the ignition switch was turned to ON.

OK:

Engine starts normally.

OK

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)
NG (for 1UR-FE)

REPLACE ECM

NG (for 3UR-FE)

REPLACE ECM

NG (for 3UR-FBE)

REPLACE ECM

16.

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

(a) Disconnect the J26 transponder key ECU assembly connector.

(b) Disconnect the A24 ECM connector.

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

Standard Resistance:

for 1UR-FE

Tester Connection

Condition

Specified Condition

J26-12 (EFII) - A24-29 (IMO)

Always

Below 1 Ω

A24-29 (IMO) - Body ground

Always

10 kΩ or higher

J26-12 (EFII) - Body ground

Always

10 kΩ or higher
for 3UR-FE, 3UR-FBE

Tester Connection

Condition

Specified Condition

J26-12 (EFII) - A24-48 (IMO)

Always

Below 1 Ω

A24-48 (IMO) - Body ground

Always

10 kΩ or higher

J26-12 (EFII) - Body ground

Always

10 kΩ or higher
OK

GO TO STEP 7

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
    No Communication in Immobiliser System (B2796)

    Data List / Active Test

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