Chart C-3 Canister Purge Check

- Chart C-3 Canister Purge Valve Check.:

- Wiring Diagram for Chart C-3 Canister Purge Check.:

CHART C-3, CANISTER PURGE CHECK (VIN X)

CIRCUIT DESCRIPTION
Canister purge is controlled by a solenoid that allows manifold vacuum to purge the canister when de-energized. The ECM supplies a ground to energize the solenoid (purge off). The solenoid is energized (no purge) by grounding the test terminal with the ingition "ON" and engine stopped, or with the engine running if the following are met:
a. Engine run time less than specified.
b. Coolant temperature below a given value.
c. Vehicle speed below a given value.
d. TPS below a given value.
If the above are not met, the purge solenoid should be de-energized, that is purge "ON".

CHART DESCRIPTION
1. Checks to see if solenoid is energized and will not allow vacuum to pass.
2. Checks to see if signal to energize solenoid (Light "ON") is present at the solenoid. Light "ON" is normal and would indicate no fault in ECM or circuit to solenoid.
3. Checks to see if solenoid passes vacuum when test terminal is un-grounded (solenoid de-energized). It should open and keep the pump from building up a vacuum.