Toyota Tundra Service Manual: Center Differential Lock Circuit (C1340)

Toyota Tundra Service Manual / Brake / Brake Control / Dynamic Control Systems / Vehicle Stability Control System / Center Differential Lock Circuit (C1340)

DESCRIPTION

The skid control ECU monitors the 2WD/4WD state from both the 4 wheel drive control ECU and the A.D.D. detection switch.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1340

Center Differential Lock Circuit

On a 4WD vehicle, a normal A.D.D. detection switch signal is input via CAN communication, but that signal continuously does not match the A.D.D. detection switch signal that is input to the skid control ECU via the direct line for 5 seconds.
  • A.D.D. detection switch (A.D.D. actuator)
  • A.D.D. detection switch (A.D.D. actuator) circuit
  • 4WD control ECU
  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When replacing the VSC actuator assembly, perform zero point calibration.

HINT:

If the transfer shift actuator cannot change from 2WD to 4WD or 4WD to 2WD, inspect and repair the touch select 2-4 and high-low system first.

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (EXI2 TERMINAL)

(a) Set the vehicle in 4WD state using the transfer position switch.

(b) Turn the ignition switch off.

(c) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(d) Disconnect the A57 skid control ECU (brake actuator assembly) connector.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Actuator Assembly))

(e) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

(f) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A57-22 (EXI2) - Body ground
  • Ignition switch ON
  • 4WD (A.D.D. detection switch ON)

Below 1.5 V

(h) Turn the ignition switch off.

(i) Connect the A57 skid control ECU (brake actuator assembly) connector.

(j) Set the vehicle in 2WD state using the transfer position switch.

(k) Disconnect the A57 skid control ECU (brake actuator assembly) connector.

(l) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A57-22 (EXI2) - Body ground
  • Ignition switch ON
  • 2WD (A.D.D.detection switch OFF)

9.5 to 14 V
OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

2.

CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - 4WD CONTROL ECU)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(b) Disconnect the A25 4WD control ECU connector.

(c) Disconnect the G1 A.D.D. actuator connector.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A57-22 (EXI2) - A25-18 (ADD)

Always

Below 1 Ω

A57-22 (EXI2) or A25-18 (ADD) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

CHECK HARNESS AND CONNECTOR (4WD CONTROL ECU - BODY GROUND)

(a) Reconnect the A25 4WD control ECU connector.

(b) Reconnect the G1 A.D.D. actuator connector.

(c) Reconnect the A57 skid control ECU (brake actuator assembly) connector.

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

*a

Component without harness connected

(4WD Control ECU)

-

-

Standard Resistance:

Tester Connection

Condition

Specified Condition

A25-18 (ADD) - Body ground

4WD (A.D.D. detection switch ON)

Below 1 Ω

2WD (A.D.D. detection switch OFF)

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

RECONFIRM DTC

(a) Clear the DTCs.

Click here

(b) Turn the ignition switch off.

(c) Start the engine.

(d) Check if the same DTC is output.

Click here

Result

Proceed to

C1340 is not output

A

C1340 is output

B
A

USE SIMULATION METHOD TO CHECK

B

REPLACE 4WD CONTROL ECU

    Zero Point Calibration of Acceleration Sensor Undone (C1336)

    Stop Light Control Relay Malfunction (C1380)

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