Toyota Tundra Service Manual: No Communication in Immobiliser System (B2796)

Toyota Tundra Service Manual / Vehicle Interior / Engine Immobiliser / Engine Immobiliser System (w/o Smart Key System) / No Communication in Immobiliser System (B2796)

DESCRIPTION

This DTC is stored when a key is inserted into the ignition key cylinder but no communication occurs between the key and transponder key ECU assembly.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

B2796

No Communication in Immobiliser System

The key ID code cannot be transmitted to the transponder key ECU assembly (1 trip detection logic*).
  • Key
  • Transponder key coil
  • Transponder key ECU assembly
  • Insert the key into the ignition key cylinder.
  • *: 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 No.

Data List and Active Test

B2796

Response

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

    Click here

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

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Click here

NEXT

2.

CHECK FOR DTC

(a) Insert and remove each registered key one at a time, and check for DTCs each time.

Click here

HINT:

  • Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.
  • If DTC B2796 is stored, check for DTCs with the next key after clearing the DTCs.

OK:

DTC B2796 is not output.

Result

Proceed to

B2796 is not output

A

DTC B2796 is output for all of the keys

B

DTC B2796 is output for any of the keys

C
A

USE SIMULATION METHOD TO CHECK

C

GO TO STEP 8

B

3.

REPLACE TRANSPONDER KEY ECU ASSEMBLY

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

Click here

NEXT

4.

REGISTER KEY

(a) Register the key.

Click here

NEXT

5.

REGISTER ECU COMMUNICATION ID

(a) Register the ECU communication ID.

Click here

NEXT

6.

CLEAR DTC

(a) Clear the DTCs.

Click here

NEXT

7.

CHECK FOR DTC

(a) Check for DTCs.

Click here

HINT:

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

OK:

DTC B2796 is not output.

Result

Proceed to

B2796 is not output

A

B2796 is output

B
A

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)
B

REPLACE KEY THAT DTC IS OUTPUT

8.

REPLACE KEY

(a) Replace the key for which the DTC was stored.

Click here

NEXT

9.

CLEAR DTC

(a) Clear the DTCs.

Click here

NEXT

10.

CHECK FOR DTC

(a) Check for DTCs.

Click here

HINT:

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

OK:

DTC B2796 is not output.

Result

Proceed to

B2796 is not output

A

B2796 is output

B
A

END (KEY WAS DEFECTIVE)
B

REPLACE TRANSPONDER KEY ECU ASSEMBLY

    Unmatched Key Code (B2795)

    Engine Immobiliser System Malfunction (B2799)

    See More:

    Toyota Tundra Service Manual > Front Door Speaker(for Crewmax): Installation
    INSTALLATION CAUTION / NOTICE / HINT HINT: Use the same procedure for the RH and LH sides. The procedure listed below is for the LH side. PROCEDURE 1. INSTALL FRONT NO. 3 SPEAKER ASSEMBLY (for 12 Speakers) (a) Attach the 3 claws to install the front No. 3 speaker assembly to the bracket. NOTICE: Do ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2026 Copyright www.ttundra.com
    0.0212