Toyota Tundra. Manual — part 2949

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

ON-VEHICLE INSPECTION

1. INSPECT 4WD CONTROL SWITCH

a. Check the harness and connector (ECU - battery and body ground).

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

Standard voltage

4WD CONTROL SWITCH TESTER CONNECTION AND SPECIFIED CONDITION
VOLTAGE

If there is a malfunction, inspect the harness or connector. If the harness is malfunctioning,
repair or replace harness or connector. If the harness or connector is normal, replace the
4WD control ECU (see REMOVAL ).

Standard resistance

4WD CONTROL SWITCH TESTER CONNECTION AND SPECIFIED CONDITION
RESISTANCE

Fig. 155: Inspecting 4WD Control Switch
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

If there is a malfunction, repair or replace the harness or connector.

Tester Connection

Condition

Specified Condition

A26-3 (IG) - Body ground Ignition switch ON

11 to 14 V

Tester Connection

Condition Specified Condition

A26-4 (GND) - Body ground Always

Below 1 ohms

2009 Toyota Tundra

2009 TRANSMISSION JF1A Transfer - Tundra

b. Check the harness and connector (switch - ECU).

1. Disconnect the A25 ECU connector.

2. Disconnect the L1 switch connector.

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

Fig. 156: Identifying A25 ECU Connector And L1 Switch Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Standard resistance

A25 ECU CONNECTOR AND L1 SWITCH TESTER CONNECTION AND
SPECIFIED CONDITION RESISTANCE

If the resistance is not as specified, repair or replace the harness or connector.

c. Check the 4WD control switch.

1. Turn the ignition switch OFF.

2. Connect the L1 switch connector.

3. Connect the A25 and A26 ECU connectors.

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

Standard voltage

A25 ECU TESTER CONNECTION AND SPECIFIED CONDITION VOLTAGE

Tester Connection

Condition Specified Condition

L1-2 (LO) - A25-13 (LO)

Always

Below 1 ohms

L1-2 (LO) - Body ground

Always 100 kohms or higher

L1-4 (GND) - Body ground Always

Below 1 ohms

L1-5 (2-4) - A25-11 (2-4)

Always

Below 1 ohms

L1-5 (2-4) - Body ground

Always 100 kohms or higher

Tester Connection

Switch Condition

Specified

2009 Toyota Tundra

2009 TRANSMISSION JF1A Transfer - Tundra

Fig. 157: Identifying A25 ECU Connectors
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

If the voltage is not as specified, check the 4WD control ECU.

d. Check the 4WD control ECU.

1. Disconnect the L1 switch connector.

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

Standard voltage

L1 SWITCH TESTER CONNECTION AND SPECIFIED CONDITION VOLTAGE

Condition

A25-11 (2-4) - Body
ground

Ignition switch ON 4WD control switch 2WD
position

Below 1.5 V

Ignition switch ON 4WD control switch 4H
position

Below 1.5 V

Ignition switch ON 4WD control switch 4L
position

10.5 to 14 V

A25-13 (LO) - Body
ground

Ignition switch ON 4WD control switch 2WD
position

10.5 to 14 V

Ignition switch ON 4WD control switch 4H
position

Below 1.5 V

Ignition switch ON 4WD control switch 4L
position

Below 1.5 V

Tester Connection

Switch Condition Specified Condition

L1-2 (LO) - Body ground Ignition switch ON

10.5 to 14 V

L1-5 (2-4) - Body ground Ignition switch ON

10.5 to 14 V

2009 Toyota Tundra

2009 TRANSMISSION JF1A Transfer - Tundra

Fig. 158: Identifying L1 Switch Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

If the voltage is not as specified, replace the 4WD control ECU (see REMOVAL ). If the
voltage is normal, replace the 4WD control switch.

REMOVAL

1. REMOVE INSTRUMENT CLUSTER FINISH PANEL ASSEMBLY (See REMOVAL )

2. REMOVE 4WD CONTROL SWITCH

a. Detach the 3 claws to remove the switch.

Fig. 159: Identifying 4WD Control Switch Claws
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

INSTALLATION

1. INSTALL 4WD CONTROL SWITCH

a. Attach the 3 claws to install the switch.

2. INSTALL INSTRUMENT CLUSTER FINISH PANEL ASSEMBLY (See INSTALLATION )

2009 Toyota Tundra

2009 TRANSMISSION JF1A Transfer - Tundra