P0443
SYSTEM DESCRIPTION
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass passage in the EVAP canister purge volume control valve changes to control the flow rate. A built-in step motor moves the valve in steps corresponding to the ECM output pulses. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor from the EVAP canister is regulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control valve uses a step motor to control the flow rate of fuel vapor from the EVAP canister. This motor has four winding phases. It operates according to the output pulse signal of the ECM. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECM does not issue the pulse signal. A certain voltage signal is issued so that the valve remains at that particular opening.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Specification data are reference values.
ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values and are measured between each terminal and (43) (ECCS ground).
ON BOARD DIAGNOSIS LOGIC
DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11v at idle.
With Consult
(1) Turn ignition switch "ON".
(2) Select "DATA MONITOR" mode with CONSULT.
(3) Wait at least 5 seconds.
OR
With Generic Scan Tool
(1) Turn ignition switch "ON" and wait at least 5 seconds.
(2) Select "MODE 7" with GST.
OR
Without Scan Tools
(1) Turn ignition "ON" and wait at least 5 seconds.
(2) Turn ignition switch "OF F", wait at least 5 seconds and then turn "ON".
(3) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
DIAGNOSTIC PROCEDURE
WIRING DIAGRAM
COMPONENT INSPECTION
EVAP Canister Purge Volume Control Valve
With Consult
1. Disconnect EVAP canister purge volume control valve harness connector.
2. Check resistance between the following terminals.
terminal (2) and terminals (1), (3)
terminal (5) and terminals (4), (6)
Resistance:
Approximately 35 - 43 Ohms [At 25°C (775°F)]
3. Reconnect EVAP canister purge volume control valve harness connector.
4. Remove EVAP canister purge volume control valve from intake manifold collector and disconnect hoses from the valve.
(Plug the purge hoses. The EVAP canister purge volume control valve harness connector should remain connected.)
5. Turn ignition switch "ON".
6. Perform "PURG VOL CONT/V" in "ACTIVE TEST" mode with CONSULT. Check that EVAP canister purge volume control valve shaft moves smoothly forward and backward according to the valve opening.
If NG, replace the EVAP canister purge volume control valve.
OR
Without Consult
1. Disconnect EVAP canister purge volume control valve harness connector.
2. Check resistance between the following terminals.
terminal (2) and terminals (1), (3)
terminal (5) and terminals (4), (6)
Resistance:
Approximately 35 - 43 Ohms [At 25°C (77°F)]
3. Reconnect EVAP canister purge volume control valve harness connector.
4. Remove EVAP canister purge volume control valve from intake manifold collector and disconnect hoses from the valve.
(Plug the purge hoses. The EVAP canister purge volume control valve harness connector should remain connected.)
5. Turn ignition switch "ON" and "OFF". Check that EVAP canister purge volume control valve shaft moves smoothly forward and backward according to the ignition switch position.
If NG, replace the EVAP canister purge volume control valve.
Evaporative Emission (EVAP) Canister Vent Control Valve (Circuit)
COMPONENT DESCRIPTION
The EVAP canister vent control valve is located on the EVAP canister and is used to seal the canister vent.
This solenoid (the EVAP canister vent control valve) responds to signals from the ECM.
When the ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the canister vent. The ability to seal the vent is necessary for the on board diagnosis of other evaporative emission control system components.
This solenoid valve is used only for diagnosis, and usually remains opened.
When the vent is closed, under normal purge conditions, the evaporative emission control system is depressurized and allows "EVAP Control System (Small Leak)" diagnosis.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Specification data are reference values.
ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values and are measured between each terminal and (43) (ECCS ground).
ON BOARD DIAGNOSIS LOGIC
DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm battery voltage is more than 11v at idle.
With Consult
(1) Turn ignition switch "ON".
(2) Select "DATA MONITOR" mode with CONSULT.
(3) Start engine and wail at least 8 seconds.
OR
With Generic Scan Tool
(1) Start engine and wait at least 8 seconds.
(2) Select "MODE 7" with GST.
OR
Without Scan Tool
(1) Start engine and wait at least 5 seconds.
(2) Turn ignition switch "OFF", wait at least 8 seconds and then turn "ON".
(3) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
DIAGNOSTIC PROCEDURE
WIRING DIAGRAM
COMPONENT INSPECTION
EVAP Canister Vent Control Valve
With Consult
Check air passage continuity.
Perform "VENT CONTROL/V" in "ACTIVE TEST" mode.
Without Consult
If NG, clean valve using air blower or replace as necessary.
If the portion (B) is rusted, replace EVAP canister vent control valve.
Make sure new O-ring is installed properly.