Diagnostic Procedures
1.Perform On-Board Diagnostic (OBD) System Check. After performing OBD system check, go to next step.
2.If DTC P0443 is present, diagnose this DTC first. Turn ignition on, with engine off. Using scan tool, check EVAP vacuum switch status. If scan tool indicates that EVAP vacuum switch is not purging, go to next step. If scan tool indicates that EVAP vacuum switch is purging, go to step 5).
3.Start engine. Using scan tool, command EVAP canister purge solenoid on, while observing EVAP vacuum switch status. If scan tool indicates that canister is purging when solenoid is commanded on, see DIAGNOSTIC AIDS. If solenoid is not purging when commanded on, go to next step.
4.Turn ignition off. Disconnect purge hose from EVAP vacuum switch. Connect a vacuum gauge to canister side of EVAP switch. Start engine. Using scan tool, command EVAP canister purge solenoid on, while observing vacuum gauge. If vacuum gauge indicates vacuum reading close to engine vacuum when solenoid is commanded on, go to next step. If vacuum reading is close to engine vacuum, go to step 7).
5.Disconnect EVAP vacuum switch harness connector. If scan tool indicates PURGE, go to step 9). If scan tool does not indicate PURGE, go to next step.
6.Turn ignition off. Disconnect PCM connector C2. Using DVOM, check continuity between EVAP vacuum switch signal circuit and ground. If DVOM reads infinity, go to step 10). If DVOM does not read infinity, go to step 12.
7.Disconnect vacuum harness from EVAP canister purge solenoid and connect vacuum gauge to manifold side of vacuum harness. If normal manifold vacuum is indicated, go to next step. If manifold vacuum is not indicated, go to step 13).
8.Rotate vacuum harness connector enough to reconnect only the manifold vacuum supply hose to solenoid. Connect vacuum gauge to the other port on solenoid. Using scan tool, command EVAP canister purge solenoid on, while observing vacuum gauge. If vacuum is indicated when solenoid is commanded on, go to step 14). If vacuum is not indicated when solenoid is commanded on, go to step 15).