Chart C-3A EVAP Solenoid Purge Valve Check

Diagnostic Chart:

Evaporative Emission Cannister Purge Valve Circuit:

CIRCUIT DESCRIPTION
The use of the Evaporative Emissions (EVAP) Canister is controlled by the Engine Control Module (ECM) through the Evaporative Emission Canister Purge valve. Only when the following conditions are satisfied, the ECM opens the vacuum passage of the EVAP canister purge valve:

1. The engine has achieved normal operating temperature.
2. Engine speed is higher than a specified value.
3. Throttle valve opening not in the idle position.
4. Engine is running within a specified load.

When all of the above conditions have been satisfied, the fuel vapor is allowed to pass from the EVAP canister through the EVAP canister purge valve and purge hose to the intake manifold.

CHART TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart.

1. Checks for an open in WHT/BLU wire between MAIN relay and EVAP canister purge valve.
2. Checks for an open or a short to ground in RED/GRN wire between EVAP canister purge valve and ECM, a faulty ECM or a faulty EVAP canister purge valve.

DIAGNOSTIC AIDS
An intermittent malfunction may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections before component replacement.