DTC P1447: EVAP Control System Purge Flow Monitoring: Procedure
- Check EVAP canister for damage or leaking. See SYSTEM/COMPONENT TESTS article. If canister is okay, go to next step. If canister is not okay, replace as necessary and retest system.
- Start engine and warm to operating temperature. Turn ignition off. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port and install vacuum gauge. See EMISSION SYSTEMS in THEORY & OPERATION article. Start engine and let idle for at least 60 seconds. While monitoring vacuum gauge, increase engine speed to 2000 RPM. Release accelerator pedal and note vacuum. Vacuum should exist with engine speed at 2000 RPM and no vacuum should exist at idle. If operation is as specified, go to next step. If operation is not as specified, turn ignition off. Check vacuum lines for clogging and check EVAP canister purge volume control solenoid valve. See DTC P0443 OR P1444: EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE. Replace as necessary and retest system.
- Check vacuum line to EVAP control system pressure sensor. See Figure. Repair or replace as necessary. If line is okay, remove pressure sensor with harness connector connected. Using vacuum pump, apply 2.8 in Hg to EVAP control system pressure sensor vacuum port. Using DVOM, measure voltage between EVAP control system pressure sensor harness connector terminal No. 2 (center wire) and ground by backprobing. With vacuum applied voltage should be .4-.6 volt and without vacuum applied voltage should be 3.0-3.6 volts. If voltage is as specified, go to next step. If voltage is not as specified, replace EVAP control system pressure sensor and retest system.
- Check EVAP canister vent control valve and "O" ring. See DTC P0446, P1446 OR P1448: EVAP CANISTER VENT CONTROL VALVE . If valve is okay, check EVAP purge line for damage or leaks. Repair or replace as necessary. If purge line is okay, check closed throttle position sensor. See DTC P0510: CLOSED THROTTLE POSITION (TP) SWITCH . If closed throttle position sensor is okay, check harness connectors for pin damage or corrosion. Repair as necessary and retest system.