DTC 0312
SYSTEM DESCRIPTION
This system controls the vacuum signal applied to the EVAP canister purge control valve. When the ECM detects any of the following conditions, current does not flow through the EVAP canister purge control solenoid valve.
The solenoid valve cuts the vacuum signal so that the EVAP canister purge control valve remains closed.
- Start switch "ON"
- Closed throttle position
- Low or high engine coolant temperature
- During deceleration
- Engine stopped
COMPONENT DESCRIPTION
EVAP canister purge control solenoid valve
The EVAP canister purge control solenoid valve responds to signals from the ECM. When the ECM sends an OFF signal, the vacuum signal (from the intake manifold to the EVAP canister purge control valve) is cut.
When the ECM sends an ON (ground) signal, the vacuum signal passes through the EVAP canister purge control solenoid valve. The signal then reaches the EVAP canister purge control valve.
EVAP canister purge control valve
When the vacuum signal is cut by EVAP canister purge control solenoid valve, EVAP canister purge control valve shuts off the EVAP purge line.
EVAPORATIVE EMISSION SYSTEM DIAGRAM
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 both DTC P1492 (0807) and P1493 (0312) are displayed, first perform "TROUBLE DIAGNOSIS FOR DTC P1492".
- 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.
Without Scan Tools
1) Start engine and warm it up to normal operating temperature.
2) Check voltage between ECM terminal (59) and (25) (ECM ground).
Voltage: 0.8 - 1.5V
Perform the following procedure before the voltage drops below 0.8V. If the voltage drops below 0.8V, cool down the engine and perform the entire procedure all over again.
3) Turn ignition switch "OFF" and wait at least 5 seconds.
4) Turn ignition switch "ON" and wait at least 15 seconds.
5) Restart engine and let it idle for at least 50 seconds.
6) Maintain the following conditions for at least 30 seconds.
Vehicle speed: 30 - 100 km/h (19 - 62 MPH)
Engine speed: 1,000 - 3,000 rpm
Gear position: Suitable gear position
Check voltage between ECM terminal (59) and (25) (ECM ground): 0.8 - 1 .5V
7) Stop the vehicle, turn ignition switch "OFF", wait at least 5 seconds, and then turn "ON".
8) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
NOTE:
- Hold the accelerator pedal as steady as possible during driving in steps 7.
- If the driving conditions are not satisfied in steps 7, restart the procedure.
- It is better that the fuel level is low.
1 Of 2:
2 Of 2:
DIAGNOSTIC PROCEDURE
COMPONENT INSPECTION
EVAP canister purge control solenoid valve
Check air passage continuity.
If NG, replace solenoid valve.
EVAP canister purge control valve
Check EVAP canister purge control valve as follows:
1. Blow air in port (A), (B) and (C), then ensure that there is no leakage.
2. Apply vacuum to port (A). [Approximately -13.3 to -20.0 kPa (-100 to -150 mmHg, -3.94 to -5.91 inHg)] Blow air in port (C) and ensure free flow out of port (B).
EVAP canister vent control valve
Check air passage continuity.
With CONSULT
Perform "VENT CONTROL/V" in "ACTIVE TEST" mode with 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 0-ring is installed properly.
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 0-ring is installed properly.
Water separator
1. Check visually for insect's nest in the water separator air inlet.
2. Check visually for cracks or flaws in the appearance.
3. Check visually for cracks or flaws in the hose.
4. Check that (A) and (C) are not clogged by blowing air into (B) with (A), and then (C) plugged.
5. In case of NG in items 2 - 4, replace the parts.
NOTE: Do not disassemble water separator