Toyota Tundra. Manual — part 2946

Fig. 143: Identifying 2WD-4WD Transfer Shift Actuator Circuit Diagram (4WD HIGH
To 2WD Switch)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

1. After the 4WD HIGH to 2WD switch is complete, inspect the 4WD detection switch

and limit switch.

Standard resistance

4WD HIGH TO 2WD TESTER CONNECTION AND SPECIFIED CONDITION

If there is a malfunction, replace the transfer shift actuator (see REMOVAL ). If the
transfer shift actuator is normal, replace the 4WD control ECU (see REMOVAL ).

6. INSPECT A.D.D. ACTUATOR

HINT:

After inspecting the 2WD-4WD transfer shift actuator, inspect the A.D.D. actuator.

a. Check the harness and connector (ECU - A.D.D. actuator).

1. Disconnect the A25 and A26 ECU connectors.

2. Disconnect the G1 actuator connector.

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

Tester Connection

Condition

Specified Condition

3 (CDL) - 7 (GND)

After 4WD HIGH to 2WD
switch is complete

100 kohms or higher

4 (TL1) - 7 (GND)

After 4WD HIGH to 2WD
switch is complete

Below 1 ohms

5 (TL3) - 7 (GND)

After 4WD HIGH to 2WD
switch is complete

100 kohms or higher

2009 Toyota Tundra

2009 TRANSMISSION JF1A Transfer - Tundra

Fig. 144: Identifying A25 And A26 ECU Connectors And G1 Actuator Connector
Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Standard resistance

A25 AND A26 ECU CONNECTORS AND G1 ACTUATOR CONNECTOR
TERMINALS TESTER CONNECTION AND SPECIFIED CONDITION

If there is a malfunction, repair or replace harness or connector. If the harness or connector is
normal, check the ECU output voltage.

b. Check the 4WD control ECU (A.D.D. actuator).

1. Connect the A25 and A26 ECU connectors.

2. Connect the G1 actuator connector.

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

Tester Connection

Condition Specified Condition

A25-9 (DL1) - G1-6 (DL1)

Always

Below 1 ohms

A25-9 (DL1) - Body ground

Always 100 kohms or higher

A25-10 (DL2) - G1-5 (DL2)

Always

Below 1 ohms

A25-10 (DL2) - Body ground

Always 100 kohms or higher

A25-15 (ADD) - G1-3 (ADD) Always

Below 1 ohms

A25-15 (ADD) - Body ground Always 100 kohms or higher
A26-1 (DM1) - G1-1 (DM1)

Always

Below 1 ohms

A26-1 (DM1) - Body ground

Always 100 kohms or higher

A26-5 (DM2) - G1-2 (DM2)

Always

Below 1 ohms

A26-5 (DM2) - Body ground

Always 100 kohms or higher

G1-4 (GND) - Body ground

Always

Below 1 ohms

2009 Toyota Tundra

2009 TRANSMISSION JF1A Transfer - Tundra

Fig. 145: Identifying A25 And A26 ECU Connectors Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Standard voltage

A25 AND A26 ECU CONNECTORS TERMINALS TESTER CONNECTION AND
SPECIFIED CONDITION

Tester Connection

Switch Condition

Specified

Condition

A26-5 (DM2) -
A26-4 (GND)

Ignition switch ON 4WD control switch 2WD --> 4H
position (during A.D.D. actuator Free to Lock
operation)

10 to 14 V

Ignition switch ON 4WD control switch 2WD --> 4H
position (A.D.D. actuator Free to Lock operation
stopped)

Below 1.5 V

A26-1 (DM1) -
A26-4 (GND)

Ignition switch ON 4WD control switch 4H --> 2WD
position (during A.D.D. actuator Lock to Free
operation)

10 to 14 V

Ignition switch ON 4WD control switch 4H --> 2WD
position (A.D.D. actuator Lock to Free operation
stopped)

Below 1.5 V

A25-9 (DL1) - A26-
4 (GND)

Ignition switch ON 4WD control switch 2WD position
(A.D.D. actuator Free)

10.5 to 14 V

Ignition switch ON 4WD control switch 2WD --> 4H
position (A.D.D. actuator Lock)

Below 1.5 V

A25-10 (DL2) -
A26-4 (GND)

Ignition switch ON 4WD control switch 2WD position
(A.D.D. actuator Free)

Below 1.5 V

Ignition switch ON 4WD control switch 2WD --> 4H
position (A.D.D. actuator Lock)

10.5 to 14 V

A25-15 (ADD) -

Ignition switch ON 4WD control switch 2WD position

10 to 14 V

Ignition switch ON 4WD control switch 2WD --> 4H

2009 Toyota Tundra

2009 TRANSMISSION JF1A Transfer - Tundra

If there is a malfunction, determine if the malfunction is on the ECU side or the actuator side
by disconnecting the connector of the A.D.D. actuator, and then checking the ECU output
voltage.

c. Check the 4WD control ECU.

1. Connect the A25 and A26 ECU connectors.

2. Disconnect the G1 actuator connector.

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

Standard voltage

G1 ACTUATOR TESTER CONNECTION AND SPECIFIED CONDITION

Fig. 146: Identifying G1 Actuator Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

If there is a malfunction, replace the 4WD control ECU (see REMOVAL ). If the voltage is
normal, inspect the A.D.D. actuator, as the voltage applied to the motor cannot be measured.

d. Inspect the A.D.D. actuator.

1. Remove the A.D.D. actuator (see REMOVAL ).

2. Check the Free to Lock switch. Connect lines via a relay as shown in the illustration, then

check that the actuator fork moves from the Free to Lock position.

A26-4 (GND)

position

Below 1.5 V

Tester Connection

Switch Condition Specified Condition

G1-3 (ADD) - G1-4 (GND) Ignition switch ON

10 to 14 V

G1-5 (DL2) - G1-4 (GND) Ignition switch ON

10.5 to 14 V

G1-6 (DL1) - G1-4 (GND) Ignition switch ON

10.5 to 14 V

2009 Toyota Tundra

2009 TRANSMISSION JF1A Transfer - Tundra