Canister Purge Solenoid: Testing and Inspection

Fig. 102 Chart C-3 Canister Purge Valve:

Fig. 103 - Wiring Diagram for Chart C-3 canister Purge Valve. VIN Z:

CHART C-3 TESTING CANISTER PURGE SOLENOID


Circuit Description:
Canister purge is controlled by a solenoid that allows manifold vacuum to purge the canister when energized. The ECM supplies a ground to energize the solenoid (purge "ON").
If the diagnostic test terminal is grounded with the engine stopped or the following is met with the engine running the purge solenoid is energized (purge "ON").
a. Engine run time after start more than 1 min.
b. Coolant temperature above 80°C.
c. Vehicle speed above 5 mph.
d. Throttle off idle. TPS signal about .75 volt.





Test Description: Numbers below refer to circled numbers 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 open.
2. Completes functional check, by grounding test terminal. This should, energize the solenoid and allow the vacuum to drop (purge "ON").
3. Checks for a complete circuit. Normally, there is battery voltage on CKT 39, and the ECM provides a ground on CKT 428.