Vehicle Stability Control System (For Hydraulic Brake Booster) Downhill Assist Control Indicator Light Does Not Come On


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK CAN COMMUNICATION LINE

CHECK FOR DTC

INSPECT DOWNHILL ASSIST CONTROL SWITCH

CHECK HARNESS AND CONNECTOR (MASTER CYLINDER SOLENOID HDCS CIRCUIT)

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DOWNHILL ASSIST CONTROL LIGHT)

VEHICLE STABILITY CONTROL SYSTEM (for Hydraulic Brake Booster) - Downhill Assist Control Indicator Light does not Come ON


DESCRIPTION

Even if the downhill assist control switch is pressed, the downhill assist control indicator light blinks and downhill assist control does not activate under the following conditions:
  1. The transfer is in H4.
  2. The brake system is malfunctioning.
  3. The temperature of the hydraulic brake booster increases and downhill assist control is temporarily canceled.

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Brake Control Dynamic Control Systems.Anti-Lock Brake System.Vehicle Stability Control System (For Hydraulic Brake Booster) Downhill Assist Control Indicator Light Does Not Come On


INSPECTION PROCEDURE

NOTICE:
When replacing the skid control ECU (master cylinder solenoid), perform calibration (LandCruiser RM00000452J00ZX.html).
1.CHECK CAN COMMUNICATION LINE

  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. Select CAN Bus Check from the System Selection Menu screen and follow the prompts on the screen to inspect the CAN bus (for LHD: LandCruiser RM000000WIB0ECX.html, for RHD: LandCruiser RM000000WIB0EEX.html).

    OK:
    CAN Bus Check indicates no malfunctions in CAN communication.
    Result
    Result
    		Proceed to
    OK
    		A
    NG (for LHD)
    		B
    NG (for RHD)
    		C


B
GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) (LandCruiser RM000001RSO0C5X.html)

C
GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) (LandCruiser RM000001RSO0BZX.html)
A


2.CHECK FOR DTC

  1. Check for DTCs (LandCruiser RM0000046KV016X.html).

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


B
REPAIR CIRCUITS INDICATED BY OUTPUT DTCS (LandCruiser RM0000045Z601DX.html)
A


3.INSPECT DOWNHILL ASSIST CONTROL SWITCH

  1. Remove the downhill assist control switch (LandCruiser RM000001PC0010X.html).



    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Brake Control Dynamic Control Systems.Anti-Lock Brake System.Vehicle Stability Control System (For Hydraulic Brake Booster) Downhill Assist Control Indicator Light Does Not Come On

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    1 - 4
    		Not pushed in
    		10 kΩ or higher
    Pushed in
    		Below 1 Ω
    Text in Illustration
    *a
    		Component without harness connected
    (Downhill Assist Control Switch)


NG
REPLACE DOWNHILL ASSIST CONTROL SWITCH (LandCruiser RM000001PC0010X.html)
OK


4.CHECK HARNESS AND CONNECTOR (MASTER CYLINDER SOLENOID HDCS CIRCUIT)

  1. Disconnect the A7 skid control ECU (master cylinder solenoid) connector.

  1. Disconnect the G158 downhill assist control switch connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A7-44 (HDCS) - G158-4
    		Always
    		Below 1 Ω
    A7-44 (HDCS) or G158-4 - Body ground
    		Always
    		10 kΩ or higher
    G158-1 - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DOWNHILL ASSIST CONTROL LIGHT)

  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 / ABS/VSC/TRC / Active Test.

    ABS/VSC/TRC
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Downhill Assist Control Light
    		Downhill assist control indicator light
    		Indicator light ON/OFF
    		Observe the combination meter.

  1. When performing the Downhill Assist Control Light Active Test, check Downhill Assist Control Light in the Data List (LandCruiser RM000001DWY02VX.html).

    ABS/VSC/TRC
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Downhill Assist Control Light
    		Downhill assist control indicator light/ ON or OFF
    		ON: Indicator light on
    OFF: Indicator light off
    		-

    Result
    Result
    		Proceed to
    Data List Display
    		Data List Display when Performing Active Test ON/OFF Operation
    ON
    		Changes between ON and OFF
    		A
    Does not change between ON and OFF (for LHD)
    		B
    Does not change between ON and OFF (for RHD)
    		C
    OFF
    		Changes between ON and OFF
    		A
    Does not change between ON and OFF (for LHD)
    		B
    Does not change between ON and OFF (for RHD)
    		C


B
REPLACE MASTER CYLINDER SOLENOID (LandCruiser RM00000171U02DX.html)

C
REPLACE MASTER CYLINDER SOLENOID (LandCruiser RM00000171U02EX.html)
A

GO TO METER / GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) (LandCruiser RM000002Z4L055X.html)