Toyota Tundra. Manual — part 374

A: Go to Next Step

5. CHECK TRANSPONDER KEY ECU (POWER SOURCE AND BODY GROUND)

a. Turn the ignition switch ON.

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

Standard voltage

TRANSPONDER KEY ECU (POWER SOURCE AND BODY GROUND) TESTER
CONNECTION SPECIFIED CONDITION CHART

Fig. 31: Identifying J26 ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE TRANSPONDER KEY ECU (see REMOVAL )

DTC B279C THEFT DETERRENT SYSTEM PRESENCE DETECTION

DESCRIPTION

If an ECM that is incompatible with the engine immobilizer system is installed, the ECM outputs this DTC.

DTC B279C THEFT DETERRENT SYSTEM PRESENCE DETECTION CONDITION CHART

Tester Connection

Condition Specified Condition

J26-1 (+B) - J26-16 (GND) Always

11 to 14 V

DTC

No.

DTC Detection Condition

Trouble

Area

B279C

ECM for vehicle without engine immobilizer system is installed on vehicle with
engine immobilizer system

ECM

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

INSPECTION PROCEDURE

1. CLEAR DTC

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

2. CHECK FOR DTC

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

OK: DTC B279C is not output.

Result

B279C THEFT DETERRENT SYSTEM PRESENCE DETECTION RESULT CHART

NG: REPLACE ECM (See REMOVAL )

NG: REPLACE ECM (See REMOVAL )

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

SECURITY INDICATOR LIGHT CIRCUIT

DESCRIPTION

When a key is registered, the transponder key ECU outputs the key registration condition by lighting up,
blinking or turning OFF the security indicator light.

WIRING DIAGRAM

Result

Proceed to

OK

A

NG (for 2UZ-FE)

B

NG (for 3UR-FE)

C

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

Fig. 32: Security Indicator Light - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSPECTION PROCEDURE

HINT:

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

1. PERFORM ACTIVE TEST BY TECHSTREAM (SECURITY INDICATOR LIGHT)

a. Select the Active Test, use the Techstream to generate a command.

b. Check that the security indicator light operation is normal.

TESTER DISPLAY - IMMOBILIZER

OK: Security indicator light turns ON and OFF.

NG: Go to step 3

OK: Go to Next Step

2. CHECK TRANSPONDER KEY ECU

a. Remove the transponder key ECU with the connector still connected (see REMOVAL ).

Tester Display

Test Part

Control Range Diagnostic Note

Security Indicator Security indicator light

ON or OFF

-

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

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

Standard voltage

TRANSPONDER KEY ECU TESTER CONNECTION SPECIFIED CONDITION CHART

Fig. 33: Identifying Transponder Key ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

NG: REPLACE TRANSPONDER KEY ECU (see REMOVAL )

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE

3. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - SECURITY

INDICATOR LIGHT)

a. Disconnect the J26 ECU connector.

b. Disconnect the K20 meter connector.

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

Standard resistance

HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - SECURITY INDICATOR
LIGHT) TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection

Condition

Specified Condition

J26-8 (IND) - Body

ground

Engine immobilizer system is

set

Alternating between 11 to 14 V and

below 1 V

Tester Connection

Condition Specified Condition

J26-8(IND) - K20-17 (LP) Always

Below 1 ohms

J26-17(LP)- Body ground

Always

10 kohms higher

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra