DTC 0903

NOTE: If both DTC P044O and P0446 are displayed, perform TROUBLE DIAGNOSIS FOR P0446 first The EVAP canister vent control valve is located on the EVAP canister and is used to seal the canister vent.







COMPONENT DESCRIPTION
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.




CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.




ECM TERMINALS AND REFERENCE VALUE
Remarks: Specification data are reference values and are measured between each terminal and (A) (ECCS ground) with a voltmeter.




ON BOARD DIAGNOSTIC LOGIC

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
With Consult
(1) Turn ignition switch "ON".
(2) Select "DATA MONITOR" mode with CONSULT.
(3) Stan 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 engine 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 1st trip 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.

With 12 volts applied to terminals (1) and (2):
No air passage between ports (A) and (B).
With No 12 volt supply to terminals (1) and (2):
Air passage between ports (A) and (B).

If removed, clean valve using air blower.
Make sure new O-ring is installed properly.

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

WIRING DIAGRAM




DIAGNOSTIC PROCEDURE

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.

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.

Pressure (Relative to atmospheric pressure) / Voltage (V)
+40 kPa (+30 mmHg +1.18 inHg) / Approximately 4.6
-9.3 kPa (-70 mmHg. -2.76 inHg) / Approximately 0.5

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

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