Toyota Tundra. Manual — part 372

HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY
AMPLIFIER) TESTER CONNECTION SPECIFIED CONDITION CHART

Fig. 25: Checking Harness And Connector (Transponder Key ECU - Transponder Key
Amplifier)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

5. REPLACE TRANSPONDER KEY AMPLIFIER

a. Temporarily replace the transponder key amplifier with a new or normally functioning one (see

REMOVAL ).

6. CHECK WHETHER ENGINE STARTS

a. Check that the engine starts normally.

OK: Engine starts.

Tester Connection

Condition Specified Condition

J26-15(CODE) - J20-4 (CODE)

Always

Below 1 ohms

J26-15(CODE) or J20-4 (CODE) - Body ground Always

10 kohms or higher

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

NG: REPLACE TRANSPONDER KEY ECU (see REMOVAL )

OK: END (TRANSPONDER KEY AMPLIFIER IS DEFECTIVE)

DTC B2799 ENGINE IMMOBILIZER SYSTEM MALFUNCTION

DESCRIPTION

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

DTC B2799 ENGINE IMMOBILIZER SYSTEM MALFUNCTION DETECTION CONDITION
CHART

WIRING DIAGRAM

Fig. 26: Engine Immobilizer System - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

HINT:

DTC

Code

DTC Detection Condition

Trouble Area

B2799

One of following conditions is met:



Error in communication between ECM and transponder key
ECU



Error in communication lines



ECU - ECM communication ID is different during
communication with transponder key ECU



Harness or
connector



Transponder key
ECU



ECM

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

When the transponder key ECU and/or ECM is replaced, reregister the ECU - ECM communication ID (see
REGISTRATION ).

1. CLEAR DTC

a. Clear the DTC (see DTC CHECK/CLEAR ).

2. CHECK FOR DTC

a. Check for DTC (see DTC CHECK/CLEAR ).

OK: B2799 is not output.

NG: Go to step 3

OK: USE SIMULATION METHOD TO CHECK (See HOW TO PROCEED WITH
TROUBLESHOOTING )

3. REREGISTER ECU - ECM COMMUNICATION ID

a. Reregister the ECU - ECM communication ID (see REGISTRATION ).

4. CLEAR DTC

a. Clear the DTC (see DTC CHECK/CLEAR ).

5. CHECK FOR DTC

a. Check for DTC (see DTC CHECK/CLEAR ).

OK: DTC B2799 is not output.

NG: Go to step 6

OK: END

6. CHECK CONNECTION OF CONNECTOR

a. Turn the ignition switch LOCK.

b. Check that the connectors are properly connected to the ECM and the transponder key ECU.

OK: Connectors are properly connected.

NG: CONNECT CONNECTOR CORRECTLY

OK: Go to Next Step

7. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM)

a. Disconnect the J26 ECU connector.

b. Disconnect the A24 ECM connector.

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

Standard resistance

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM) TESTER
CONNECTION SPECIFIED CONDITION CHART

Fig. 27: Checking Harness And Connector (Transponder Key ECU - ECM)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step

8. REPLACE TRANSPONDER KEY ECU

a. Temporarily replace the transponder key ECU with a new or normally functioning one (see

REMOVAL ).

9. CLEAR DTC

a. Clear the DTC (see DTC CHECK/CLEAR ).

10. CHECK FOR DTC

Tester Connection

Condition Specified Condition

J26-13(EFIO) - A24-40 (IMI)

Always

Below 1 ohms

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

J26-13(EFIO) or A24-40 (IMI) - Body ground

Always

10 kohms or higher

J26-12(EFII) or A24-29 (IMO) - Body ground

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra