DTC 0903

NOTE: If both DTC P0440 and P0446 are displayed, perform TROUBLE DIAGNOSIS FOR DTC P0446 first.







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.




DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
Perform "Procedure for malfunction A". If the DTC cannot be confirmed, perform "Procedure for malfunction B".

Procedure for Malfunction A
With Consult
(1) Turn ignition switch "ON".
(2) Select "DATA MONITOR" mode with CONSULT.
(3) Start engine and wait at least 5 seconds.

OR

With GST
(1) Start engine and wait at least 5 seconds.
(2) Select "MODE 7" with GST.

OR

No Tools
(1) Start and wait at least 5 seconds.
(2) Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
(3) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.

OVERALL FUNCTION CHECK
Use this procedure to check the overall function of the EVAP canister vent control valve circuit. During this check, a DTC might not be confirmed.

Procedure for Malfunction B




(1) Remove EVAP canister vent control valve from EVAP canister and disconnect hoses from the valve.
(2) Check air passage continuity.

Condition / Air passage continuity between (A) and (B)
12V direct current supply between terminals (1) and (2) / No
No supply / Yes







DIAGNOSTIC PROCEDURE

EC-VENT/V-01 Evaporative Emission (EVAP) Canister Vent Control Valve (DTC P0446):

WIRING DIAGRAM

COMPONENT INSPECTION
EVAP Canister Vent Control Valve
Check air passage continuity.




Condition / Air passage continuity between (A) and (B)
12V direct current supply between terminals (1) and (2) / No
No supply / Yes

If NG, clean valve using air blower or replace as necessary.
Make sure new O-ring is installed properly.

Pressure (Relative to atmospheric pressure) / Voltage(V)
0 kPa(0 mmHg, 0 inHg, 0 psi) / 3.0 - 3.6
-9.3 kPa ( -70 mmHg, -2.76 inHg, -1.35 psi) / 0.4 - 0.6

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 terminal (2) and engine ground.

Pressure (Relative to atmospheric pressure) / Voltage
0 kPa (0 psi) / 3.0 - 3.6
-9.3 kPa (-1.35 psi) / 0.4 - 0.6

CAUTION: Always calibrate the vacuum pump gauge when using it.

5. If NG, replace EVAP control system pressure sensor.

EVAP Canister Breather Valve
1. Remove rubber tube from EVAP canister vent control valve.




2. Apply gauze to rubber tube end.
3. Check air passage continuity as shown in figure.
4. If NG, clean valve using air blower or replace as necessary.