Dtc P0443 Evaporative Emission Control System Purge Control Valve Circuit

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

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST BY INTELLIGENT TESTER (VSV for EVAP)

CHECK ECM (PRG VOLTAGE)

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

CHECK WIRE HARNESS (ECM - VSV for EVAP)

CHECK WIRE HARNESS (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 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 Grs190.3Uz-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 a malfunction is 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 Grs190.3Uz-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. Turn the engine switch on (IG) 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
    		Suction air
    VSV is OFF
    		No suction air


OK
CHECK FOR INTERMITTENT PROBLEMS
NG


2.CHECK ECM (PRG VOLTAGE)
Lexus Gs430, Gs300. Uzs190 Grs190.3Uz-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 of the ECM.

    Standard voltage:
    Tester Connection
    		Specified Condition
    E8-11 (PRG) - E7-7 (E1)
    		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 WIRE HARNESS (ECM - VSV for EVAP)
Lexus Gs430, Gs300. Uzs190 Grs190.3Uz-Fe Engine Control System.Sfi System. Dtc P0443 Evaporative Emission Control System Purge Control Valve Circuit

  1. Disconnect the VSV for EVAP connector.

  1. Disconnect the E8 ECM connector.

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

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


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


5.CHECK WIRE HARNESS (EFI NO. 2 FUSE - VSV for EVAP)
Lexus Gs430, Gs300. Uzs190 Grs190.3Uz-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.

  1. Disconnect the VSV connector.

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

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


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

INSPECT ECM POWER SOURCE CIRCUIT