Dtc P0443 Evaporative Emission Control System Purge Control Valve Circuit

Engine. Lexus Gs430, Gs300. Uzs190 Grs190
3Gr-Fe Engine Control System. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST BY INTELLIGENT TESTER (VSV FOR EVAP)

INSPECT ECM (CHECK VOLTAGE)

INSPECT DUTY VACUUM SWITCHING VALVE (OPERATION OF VSV FOR EVAP)

CHECK HARNESS AND CONNECTOR (ECM - VSV FOR EVAP)

CHECK HARNESS AND CONNECTOR (EFI NO. 2 FUSE - VSV FOR EVAP)

DTC P0443 Evaporative Emission Control System Purge Control Valve Circuit


DESCRIPTION

To reduce HC emissions, evaporated fuel from the fuel tank is routed through the charcoal canister to the intake manifold for combustion in the cylinders.
The ECM changes the duty signal to the VSV for EVAP so that the intake quantity of HC emissions is appropriate for the driving conditions (engine load, engine speed, vehicle speed, etc.) after the engine is warmed up.

DTC NO.
DTC Detection Condition
Trouble Area
P0443
Proper response to ECM command does not occur
(1 trip detection logic)
  1. Open or short in VSV circuit for EVAP
  2. VSV for EVAP
  3. ECM

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0443 Evaporative Emission Control System Purge Control Valve Circuit


INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
1.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (VSV FOR EVAP)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0443 Evaporative Emission Control System Purge Control Valve Circuit

  1. Disconnect the vacuum hose from the VSV for EVAP.

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine and turn the tester ON.

  1. Enter the following menus: Powertrain / Engine / Active Test / Activate the VSV for EVAP Control. Press the right or left button.

  1. Check if air is sucked into the port when operating the VSV for EVAP using the intelligent tester.

    Standard:
    Tester Operation
    		Specified Condition
    VSV is ON
    		Air is sucked
    VSV is OFF
    		No air is sucked


OK
CHECK FOR INTERMITTENT PROBLEMS
NG


2.INSPECT ECM (CHECK VOLTAGE)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0443 Evaporative Emission Control System Purge Control Valve Circuit

  1. Turn the engine switch on (IG).

  1. Measure the voltage between the terminals or the E8 and E7 ECM connectors.

    Standard voltage:
    Tester Connection
    		Specified Condition
    PRG (E8-11) - E1 (E7-7)
    		9 to 14 V


OK
REPLACE ECM
NG


3.INSPECT DUTY VACUUM SWITCHING VALVE (OPERATION OF VSV FOR EVAP)


NG
REPLACE DUTY VACUUM SWITCHING VALVE
OK


4.CHECK HARNESS AND CONNECTOR (ECM - VSV FOR EVAP)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0443 Evaporative Emission Control System Purge Control Valve Circuit

  1. Disconnect the E8 ECM connector.

  1. Disconnect the VSV for EVAP connector.

  1. Measure the resistance between the wire harness side connectors.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    VSV for EVAP (E18-2) - PRG (E8-11)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    VSV for EVAP (E18-2) or PRG (E8-11) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


5.CHECK HARNESS AND CONNECTOR (EFI NO. 2 FUSE - VSV FOR EVAP)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0443 Evaporative Emission Control System Purge Control Valve Circuit

  1. Remove the EFI NO. 2 fuse from the engine room No. 2 relay block and junction block.

  1. Disconnect the VSV for EVAP connector.

  1. Measure the resistance between the wire harness side connectors.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    VSV for EVAP (E18-1) - EFI NO. 2 fuse (2)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    VSV for EVAP (E18-1) or EFI NO. 2 fuse (2) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

INSPECT ECM POWER SOURCE CIRCUIT