With Generic Scan Tool
SYSTEM DESCRIPTION
This system automatically controls flow rate of fuel vapor from EVAP canister. The EVAP canister purge volume control valve changes the opening of the vapor by-pass passage to control the flow rate. This valve is actuated by a step motor built into the valve, which moves the valve in the axial direction in steps corresponding to the ECM output pulses, the opening of the valve is varied to allow for optimum engine control. The optimum value stored in the ECM is determined by taking into consideration various engine conditions. When the engine operates, the flow rate is proportionally regulated as the air flow increases.
COMPONENT DESCRIPTION
The EVAP canister purge volume control valve is operated by a step motor for control of flow rate of fuel vapor from EVAP canister. This motor has four winding phases and is actuated by the output pulse signal of ECM which turns ON and OFF two windings each in sequence. Each time the valve opens or closes to change the flow rate, an ON pulse is issued. When no change in the flow rate is needed, the valve remains at a certain opening, hence no pulse signal output is issued.
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 (25) (ECCS ground).
ON BOARD DIAGNOSIS LOGIC
DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
CAUTION: Always drive vehicle at a safe speed.
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.
- This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test is expected to be easier, it is unnecessary to lift the vehicle.
TESTING CONDITION:
Always perform test at a temperature of 5°C (41°F) or more.
With Generic Scan Tool
1) Lift up vehicle.
2) Start engine and warm it up to normal operating temperature.
3) Select "MODE 1" with GST.
4) Check coolant temperature.
Coolant temperature: 40 - 100°C (104 - 212°F)
Be sure that water temperature does not exceed 100°C.
If it becomes higher than 10000, cool down the engine and perform the procedure again from the beginning.
5) Turn ignition switch "OFF" and wait at least 5 seconds.
6) Turn ignition switch "ON" and wait at least 15 seconds.
7) Restart engine and let it idle for at least 50 seconds.
8) Maintain the following conditions for at least 10 seconds.
Gear position: Suitable gear position
Vehicle speed: 30 - 100 km/h (19 - 62 MPH)
Engine speed: 1,000 - 3,000 rpm
Coolant temperature: 40 - 100°C (104 - 212°F)
9) Select "MODE 7" with GST.
NOTE:
- Hold the accelerator pedal as steady as possible during driving in steps 8.
- If the driving conditions are not satisfied in steps 8, restart the procedure.
- It is better that the fuel level is low.
DIAGNOSTIC PROCEDURE
COMPONENT INSPECTION
EVAP canister purge volume control valve
Without TOOLS
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 30 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" and ensure the EVAP canister purge volume control valve shaft smoothly moves forward and backward according to the ignition switch position.
If NG, replace the EVAP canister purge volume control valve.
EVAP control system pressure sensor
1. Remove EVAP control system pressure sensor with its harness connector connected.
2. Remove hose from EVAP control system pressure sensor.
3. Use pump to apply vacuum and pressure to EVAP control system pressure sensor as shown in figure.
4. Check output voltage between ECM terminal (62) and (25) (ECM ground).
CAUTION:
- Always calibrate the vacuum pump gauge when using it.
- Do not apply below -20 kPa (-150 mmHg, -5.91 inHg) or over 20 kPa (150 mmHg, 5.91 inHg) of pressure.
5. If NG, replace EVAP control system pressure sensor.
EVAP canister vent control valve
Check air passage continuity.
Without TOOLS
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.