Code 0903

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 a necessary part of the diagnosis algorithms for other evaporative loss 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 loss system is depressurized allowing "EVAP Control System (Small Leak)" diagnosis.




DIAGNOSTIC CHART




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

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

OR

GST
1) Start engine and wait for at least 5 seconds.
2) Select "MODE 3" with GST.

OR

NO TOOLS
1) Start engine and wait for at least 5 seconds.
2) Turn ignition switch "OFF", wait for at least 5 seconds and then turn "ON".
3) Perform "Diagnostic Test Mode 11 (Self-diagnostic results)" with ECM.

OVERALL FUNCTION CHECK
This procedure can be used for checking 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.

COMPONENT INSPECTION
EVAP canister vent control valve




Check air passage continuity.




If NG, clean valve using air blower or replace as necessary.

EVAP control system pressure sensor




1. Remove EVAP control system pressure sensor from bracket with its harness connector connected.
2. Remove hose from EVAP control system pressure sensor.
3. Apply vacuum and pressure to EVAP control system pressure sensor with pump as shown in figure.
4. Check output voltage between terminal (2) and engine ground.




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




WIRING DIAGRAM