Dtc C1736 Front Suspension Control Valve Rh Malfunction

Suspension. Land Cruiser. Urj200, 202 Grj200 Vdj200
Suspension Control. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FRONT SPRING RATE SWITCHING VALVE)

RECONFIRM DTC OUTPUT

CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - FRONT SUSPENSION CONTROL VALVE)

CHECK HARNESS AND CONNECTOR (BODY GROUND BETWEEN ECU - FRONT SUSPENSION CONTROL VALVE)

INSPECT FRONT SUSPENSION CONTROL VALVE

CHECK HARNESS AND CONNECTOR (BODY GROUND BETWEEN ECU - NO. 1 HEIGHT CONTROL VALVE)

CHECK HARNESS AND CONNECTOR (NO. 1 HEIGHT CONTROL VALVE - SUSPENSION CONTROL ECU)

DTC C1736 Front Suspension Control Valve RH Malfunction

DTC C1737 Front Suspension Control Valve LH Malfunction


DESCRIPTION

In order to decrease roll angle/pitch angle, the suspension control ECU turns the spring rate switching valve in the front suspension control valve off/on to change the fluid lines when the acceleration sensor or yaw rate sensor signal is input into the suspension control ECU. Normally, the spring rate switching valve is open.

DTC Code
Detection Condition
Trouble area
C1736
When either of the following is detected:
  1. With the spring rate switch valve RH not activated, an open signal of the spring rate switch valve RH is detected for 1 second or more.
  2. With the spring rate switch valve RH activated, a short signal of the spring rate switch valve RH is detected 8 times successively.
  1. Harness or connector
  2. Front suspension control valve RH (Front spring rate switching valve RH)
  3. Suspension control ECU
  4. No. 1 height control valve
C1737
When either of the following is detected:
  1. With the spring rate switch valve LH not activated, an open signal of the spring rate switch valve LH is detected for 1 second or more.
  2. With the spring rate switch valve LH activated, a short signal of the spring rate switch valve LH is detected 8 times successively.
  1. Harness or connector
  2. Front suspension control valve LH (Front spring rate switching valve LH)
  3. Suspension control ECU
  4. No. 1 height control valve

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.Suspension Control.Suspension Control System. Dtc C1736 Front Suspension Control Valve Rh Malfunction


INSPECTION PROCEDURE

NOTICE:
  1. Before performing troubleshooting, inspect the connectors of related circuits.
  2. If the suspension control ECU or height control sensor is replaced, the vehicle height offset calibration must be performed (Click here).
HINT:
Power is supplied to the front suspension control valve and No. 1 height control valve from the suspension control ECU. If a short occurs in the power supply circuit in the No. 1 height control valve, DTC C1736 and/or C1737 will be stored. In this case, DTC C1741, C1742, C1743, C1744, C1753, C1754 and/or C1755 will also be stored.
1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FRONT SPRING RATE SWITCHING VALVE)

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine and turn the tester on.

  1. Select the Active Test mode on the intelligent tester.

  1. Check the operation of the front spring rate switching valve solenoid when operating the solenoid with the intelligent tester.

    AHC
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    FR Gas Spring Switch Valve
    		Front spring rate switching valve RH
    		ON or OFF
    		When the FR Gas Spring Switch Valve item of the Active Test is operated, the FR Gas Spring Switch Valve item of the Data List changes to ON/OFF.
    FL Gas Spring Switch Valve
    		Front spring rate switching valve LH
    		ON or OFF
    		When the FL Gas Spring Switch Valve item of the Active Test is operated, the FL Gas Spring Switch Valve item of the Data List changes to ON/OFF.
    OK:
    The front spring rate switching valve operates.


NG
Go to step 3
OK


2.RECONFIRM DTC OUTPUT

  1. Clear the DTCs (Click here).

  1. Perform a road test.

  1. Check for DTCs.

    Result
    Result
    		Proceed to
    DTC is output
    		A
    DTC is not output
    		B


B
USE SIMULATION METHOD TO CHECK (Click here)
A

REPLACE SUSPENSION CONTROL ECU (Click here)

3.CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - FRONT SUSPENSION CONTROL VALVE)

  1. Disconnect the N10*1 and/or N12*2 front suspension control valve connector.

    HINT:
    *1: for RH
    *2: for LH


  1. Disconnect the K36 ECU connector.


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Suspension Control.Suspension Control System. Dtc C1736 Front Suspension Control Valve Rh Malfunction

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    K36-11 (CRFR) - N10-1 (CRFR)
    		Always
    		Below 1 Ω
    K36-11 (CRFR) - Body ground
    		Always
    		10 kΩ or higher
    K36-23 (CRFL) - N12-1 (CRFL)
    		Always
    		Below 1 Ω
    K36-23 (CRFL) - Body ground
    		Always
    		10 kΩ or higher
    K36-1 (SLB) - N10-2 (SLB)
    		Always
    		Below 1 Ω
    K36-1 (SLB) - N12-2 (SLB)
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK HARNESS AND CONNECTOR (BODY GROUND BETWEEN ECU - FRONT SUSPENSION CONTROL VALVE)

  1. Disconnect the K36 ECU connector.

  1. Disconnect the N10*1 and/or N12*2 front suspension control valve connector.

    HINT:
    *1: for RH
    *2: for LH


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Suspension Control.Suspension Control System. Dtc C1736 Front Suspension Control Valve Rh Malfunction

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    K36-1 (SLB) - Body ground
    		Always
    		10 kΩ or higher


NG
Go to step 6
OK


5.INSPECT FRONT SUSPENSION CONTROL VALVE

  1. Connect the N10 and/or N12 front suspension control valve connector.



    Land Cruiser. Urj200, 202 Grj200 Vdj200.Suspension Control.Suspension Control System. Dtc C1736 Front Suspension Control Valve Rh Malfunction

  1. Disconnect the K36 ECU connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    K36-11 (CRFR) - K36-1 (SLB)
    		at 20°C (68°F)
    		4.58 to 5.02 Ω
    K36-23 (CRFL) - K36-1 (SLB)
    		at 20°C (68°F)
    		4.58 to 5.02 Ω


NG
REPLACE FRONT SUSPENSION CONTROL VALVE (Click here)
OK

REPLACE SUSPENSION CONTROL ECU (Click here)

6.CHECK HARNESS AND CONNECTOR (BODY GROUND BETWEEN ECU - NO. 1 HEIGHT CONTROL VALVE)

  1. Disconnect the N4 No. 1 height control valve connector.

  1. Disconnect the K36 ECU connector.



    Land Cruiser. Urj200, 202 Grj200 Vdj200.Suspension Control.Suspension Control System. Dtc C1736 Front Suspension Control Valve Rh Malfunction

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    K36-1 (SLB) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


7.CHECK HARNESS AND CONNECTOR (NO. 1 HEIGHT CONTROL VALVE - SUSPENSION CONTROL ECU)

  1. Disconnect the N4 No. 1 height control valve connector.



  1. Disconnect the K36 ECU connector.


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Suspension Control.Suspension Control System. Dtc C1736 Front Suspension Control Valve Rh Malfunction

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    K36-1 (SLB) - N4-6 (SLB)
    		Always
    		Below 1 Ω
    K36-7 (SLFR) - N4-4 (SLFR)
    		Always
    		Below 1 Ω
    K36-7 (SLFR) - Body ground
    		Always
    		10 kΩ or higher
    K36-8 (SLFL) - N4-3 (SLFL)
    		Always
    		Below 1 Ω
    K36-8 (SLFL) - Body ground
    		Always
    		10 kΩ or higher
    K36-9 (SLRR) - N4-1 (SLRR)
    		Always
    		Below 1 Ω
    K36-9 (SLRR) - Body ground
    		Always
    		10 kΩ or higher
    K36-10 (SLAC) - N4-7 (AHC-)
    		Always
    		Below 1 Ω
    K36-10 (SLAC) - Body ground
    		Always
    		10 kΩ or higher
    K36-22 (SLRL) - N4-2 (SLRL)
    		Always
    		Below 1 Ω
    K36-22 (SLRL) - Body ground
    		Always
    		10 kΩ or higher
    K36-29 (SLRG) - N4-5 (SLRG)
    		Always
    		Below 1 Ω
    K36-29 (SLRG) - Body ground
    		Always
    		10 kΩ or higher
    K36-30 (SLFG) - N4-8 (SLFG)
    		Always
    		Below 1 Ω
    K36-30 (SLFG) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE NO. 1 HEIGHT CONTROL VALVE (Click here)