Last Modified: 11-29-2007 1.6 G
Service Category: Drivetrain Section: Transfer/4wd/Awd
Model Year: 2008 Model: Sequoia Doc ID: RM0000030KN003X
Title: JF3A TRANSFER / 4WD / AWD: 4WD CONTROL SWITCH: ON-VEHICLE INSPECTION (2008 Sequoia)

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:

Tester Connection

Condition

Specified Condition

A26-3 (IG) - Body ground

Ignition switch ON

11 to 14 V

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 JF3A TRANSFER / 4WD / AWD: 4WD CONTROL ECU: REMOVAL (2008 Sequoia) .

Standard Resistance:

Tester Connection

Condition

Specified Condition

A26-4 (GND) - Body ground

Always

Below 1 Ω

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

(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.



Standard Resistance:

Tester Connection

Condition

Specified Condition

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

Always

Below 1 Ω

L1-2 (LO) - Body ground

Always

10 kΩ or higher

L1-4 (GND) - Body ground

Always

Below 1 Ω

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

Always

Below 1 Ω

L1-5 (2-4) - Body ground

Always

10 kΩ or higher

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:

Tester Connection

Switch Condition

Specified 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

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:

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

If the voltage is not as specified, replace the 4WD control ECU JF3A TRANSFER / 4WD / AWD: 4WD CONTROL ECU: REMOVAL (2008 Sequoia) . If the voltage is normal, replace the 4WD control switch.