Chart C-3 EVAP Canister Purge Valve Check
Canister Purge Check Valve Diagnostic Chart:
Canister Purge Check Valve Circuit:
CIRCUIT DESCRIPTION
Canister purge is controlled by a solenoid that allows vacuum to purge the canister when energized. The Powertrain Control Module (PCM) supplies a Pulse Width Modulated (PWM) ground to energize the solenoid (purge "ON").
If the Data Link Connector (DLC) diagnostic Evaporative (EVAP) request terminal is grounded with the engine stopped or the following is met with the engine running, the purge solenoid is energized (purge "ON").
^ Engine run time after start more than 20 seconds on a warm engine or 2.5 minutes on a cold engine.
^ Engine coolant temperature above 60°C (l58°F).
^ Intake Air Temperature (IAT) is above 9.5°C (50°F).
CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Checks to see if the solenoid is opened or closed. The solenoid is normally de-energized in this step, so it should be closed.
2. Completes functional check. This should normally energize the solenoid and allow vacuum to the gauge (purge "ON").
DIAGNOSTIC AIDS
^ Inspect the canister for cracks or fuel saturation.
^ Inspect fuel vapor lines from the fuel tank or intake for leaks, being disconnected or sharp bends blocking the flow of vapors.