Evaporative Emission (EVAP) Control System Diagnosis

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

DIAGNOSIS
^ EVAP canister purge valve operation is covered and diagnosed in DTCs P0440, P0446, and P1441.
^ [1][2]EVAP vent solenoid operation is covered and diagnosed in DTCs P0440, P0442, and P0446.
^ Fuel tank pressure sensor operation is covered and diagnosed in DTCs P0440, P0442, P0446, P0452, P0453, P1441, and Evaporative Emission System Check.
^ An open or shorted circuit in the EVAP canister purge valve and [1][2]EVAP vent solenoid can also be diagnosed in PCM Outputs Diagnosis.

DIAGNOSTIC AIDS
Check for the following conditions:
^ Poor electrical connection at PCM. Inspect harness electrical connectors for the following conditions:
- Backed out terminals
- Improper mating
- Broken locks
- Improperly formed
- Damaged terminals
- Poor terminal to wire connection
^ Damaged harness-Inspect the wiring harness for damage. If the harness appears to be OK observe the Fuel Tank Vacuum Pressure display on the scan tool while moving electrical connectors and wiring harnesses related to the sensor. A change in the display will indicate the location of the malfunction.
^ Incorrect purge or vacuum source line routing. Verify that the source vacuum and purge lines to the EVAP canister purge solenoid valve are not switched.