Dtc C1746/46 Gate Solenoid Valve Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (REAR GATE SOLENOID)

CHECK HARNESS AND CONNECTOR (GATE SOLENOID VALVE - SUSPENSION CONTROL ECU)

INSPECT NO. 2 HEIGHT CONTROL VALVE (GATE SOLENOID VALVE)

DTC C1746/46 Gate Solenoid Valve Circuit


DESCRIPTION

The suspension control ECU opens the gate solenoid valve (No. 2 height control valve) to allow compressed air to flow into the height control cylinder (pneumatic cylinder) and raise the vehicle height.
The gate solenoid valve (No. 2 height control valve) opens and closes the passage between the right and left height control cylinders (pneumatic cylinders).
The No. 2 height control valve consists of a leveling solenoid valve and a gate solenoid valve.
The gate solenoid valve opens and closes the passage between the height control compressor and the height control cylinder (pneumatic cylinder).

DTC Code
DTC Detection Condition
Trouble Area
C1746/46
Either condition is met:
  1. With the height control valve inactivated, an open signal of the height control valve is detected for 1 second or more.
  2. With the height control valve activated, a short signal of the valve is detected 8 times successively.
  1. Harness or connector
  2. Gate solenoid valve (No. 2 height control valve)
  3. Suspension control ECU
HINT:
  1. Once the suspension control ECU stores DTC C1746/46 in memory, vehicle height control is suspended until a normal signal is input to the suspension control ECU from the height control valves. However, control is resumed if the ignition switch is turned off and then to ON again.
  2. Malfunction in the gate solenoid valve:
    Height control operation is suspended and the height control indicator does not change by operating the height control switch.

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Suspension Control.Air Suspension System. Dtc C1746/46 Gate Solenoid Valve Circuit


INSPECTION PROCEDURE

NOTICE:
When replacing the suspension control ECU, perform registration (LandCruiser RM000003X4500TX.html).
HINT:
If DTC C1782/82 is output at the same time as C1746/46, perform the inspection necessary for DTC C1782/82 first (LandCruiser RM000001N9301JX.html).
1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (REAR GATE SOLENOID)

  1. Turn the ignition switch off.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

  1. Enter the following menus: Chassis / Air suspension / Active Test.

    Air Suspension
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Rear Gate Solenoid
    		Gate solenoid valve
    		ON or OFF
    1. The operating sound of the solenoid (clicking sound) can be heard.
    2. When the Active Test is performed, Rear Gate Solenoid in the Data List changes between ON and OFF accordingly.
    OK:
    Operation of solenoid (clicking sound) can be heard.
    Result
    Result
    		Proceed to
    NG
    		A
    OK (When troubleshooting according to problem symptoms table)
    		B
    OK (When troubleshooting according to DTC chart)
    		C


B
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (LandCruiser RM000001SGQ021X.html)

C
USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMJ00XX.html)
A


2.CHECK HARNESS AND CONNECTOR (GATE SOLENOID VALVE - SUSPENSION CONTROL ECU)

  1. Disconnect the S7 gate solenoid valve connector.

  1. Disconnect the A14 suspension control ECU connector.

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

    Standard Resistance:
    Tester Connection
    		 Condition
    		Specified Condition
    S7-1 (LH+) - A14-15 (SLRL)
    		 Always
    		 Below 1 Ω
    S7-1 (LH+) - Body ground
    		 Always
    		 10 kΩ or higher
    S7-2 (E) - Body ground
    		 Always
    		 Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT NO. 2 HEIGHT CONTROL VALVE (GATE SOLENOID VALVE)

  1. Turn the ignition switch off.

  1. Remove the No. 2 height control valve (LandCruiser RM000002FOA01NX.html).



    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Suspension Control.Air Suspension System. Dtc C1746/46 Gate Solenoid Valve Circuit

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

    Standard Resistance:
    Tester Connection
    		 Condition
    		Specified Condition
    1 (LH+) - 2 (E)
    		20°C (68°F)
    		17.5 to 21.5 Ω
    Text in Illustration
    *a
    		Component without harness connected
    (No. 2 Height Control Valve)

  1. Connect the positive (+) lead of the battery to terminal 1 (LH+) and the negative (-) lead to terminal 2 (E) of the solenoid valve connector. Then check that the valve makes an operating sound.

    OK:
    Operation of solenoid (clicking sound) can be heard.


NG
REPLACE NO. 2 HEIGHT CONTROL VALVE ASSEMBLY (LandCruiser RM000002FOA01NX.html)
OK

REPLACE SUSPENSION CONTROL ECU (LandCruiser RM000002BGR01UX.html)