System Diagnosis - Evaporative Emission Controls (EEC)

Chart C-3.:

Evaporative Control Circuit.:

CIRCUIT DESCRIPTION:

The canister purge is controlled by a solenoid that allows vacuum to purge the fuel vapor canister when energized. The ECM supplies a ground to power the solenoid. If the diagnostic test terminal is grounded with the engine not running, or the following conditions exists with the engine running, the purge solenoid is energized (purge "ON").

^ The engine run time after start more than 45 seconds cold and/or 20 seconds when coolant temperature is greater than 85°C (185°F).
^ The coolant temperature is above 70°C (158°F).

NOTE: Because of all the possible color code combinations used on electrical wiring diagrams, always refer to SCHEMATIC DIAGRAMS/ELECTRICAL AND ELECTRONIC WIRING DIAGRAMS/ECM CONNECTOR IDENTIFICATION for correct color code identification of circuit.

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

1. Checks the CCP solenoid for proper operation.

2. Completes functional check. This should normally energize the solenoid and allow the vacuum to drop (Purge "ON").