Toyota Tundra. Manual — part 373

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

Result

DTC RESULT CHART

B: REPLACE ECM (See REMOVAL )

C: REPLACE ECM (See REMOVAL )

D: REPLACE ECM (See REMOVAL

A: END (TRANSPONDER KEY ECU IS DEFECTIVE)

DTC B279A THEFT DETERRENT SYSTEM COMMUNICATION LINE HIGH FIXATION

DESCRIPTION

If the communication line (EFIO-IMI) to the transponder key ECU is stuck on HI output, the ECM outputs this
DTC.

B279A THEFT DETERRENT SYSTEM COMMUNICATION LINE HIGH FIXATION DTC
DETECTION CONDITION CHART

WIRING DIAGRAM

Result

Proceed to

DTC B2799 is not output

A

DTC B2799 is output (for 2UZ-FE)

B

DTC B2799 is output (for 3UR-FE)

C

DTC B2799 is output (for 3UR-FBE)

D

DTC

No.

DTC Detection Condition

Trouble Area

B279A

When communication line (EFIO-IMI) between ECM and transponder
key ECU is stuck on HI output for 6 seconds or more



Harness or
connector



Transponder key
ECU



ECM

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

Fig. 28: Theft Deterrent System Communication Line High Fixation - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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 ).

Result

DTC RESULT CHART

HINT:

If any DTCs other than B279A are output, troubleshoot those DTCs first.

B: Go TO DIAGNOSTIC TROUBLE CODE CHART

A: Go to Next Step

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

a. Disconnect the J26 ECU connector.

b. Disconnect the A24 ECM connector.

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

Result

Proceed to

DTC B279A is output

A

DTC B279A and other DTCs are output

B

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

Standard resistance

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

Standard voltage

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

Fig. 29: 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

Tester Connection

Condition Specified Condition

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

Always

Below 1 ohms

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

10 kohms or higher

Tester Connection

Condition Specified Condition

J26-13 (EFIO) - Body ground

Always

Below 1 V

A24-40 (IMI) - Body ground

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra

4. CHECK TRANSPONDER KEY ECU (OUTPUT)

a. Measure the waveform.

Waveform 1 (Reference)

TRANSPONDER KEY ECU (OUTPUT) WAVEFORM 1 REFERENCE

Fig. 30: Identifying J26 ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

OK: Waveform is output normally (see Fig. 30).

Result

TRANSPONDER KEY ECU (OUTPUT) RESULT CHART

B: REPLACE ECM (See REMOVAL )

C: REPLACE ECM (See REMOVAL )

Terminal No. (Symbols)

Tool Setting

Switch Condition

J26-13(EFIO) - J26-16 (GND) 10V/DIV., 500 msec./ DIV. Ignition switch ON

Result

Proceed to

Waveform is not output normally

A

Waveform is output normally (for 2UZ-FE)

B

Waveform is output normally (for 3UR-FE)

C

2009 Toyota Tundra

2009 ACCESSORIES AND EQUIPMENT Engine Immobilizer - Tundra