This DTC tests for undesired intake manifold vacuum flow to the evaporative emission (EVAP) system. The engine control module (ECM) seals the EVAP system by commanding the EVAP canister purge solenoid valve OFF and the EVAP canister vent solenoid valve ON. The ECM monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. If vacuum in the EVAP system is more than a predetermined value within a predetermined time, this DTC sets. The preceding table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent solenoid valves.
Conditions for Setting the DTC
• The ECM detects vacuum during a non-purge condition.
• The fuel tank vacuum is greater than 4 inches H2O or less than -4 in H2O for 5 seconds within 10 minutes of cold start.
• The 10 minute test must be completed before this DTC will set.
Evaporative Emission Canister Purge Solenoid Valve Replacement
1 Remove the air cleaner assembly from the studs and reposition to the side.
2 Disconnect the evaporative emission (EVAP) canister purge valve electrical connector (1).
3 Disconnect the EVAP canister purge valve tube from the intake manifold. Refer to Plastic Collar Quick Connect Fitting Service .
4 Disconnect the chassis EVAP vapor line from the EVAP canister purge valve. Refer to Plastic Collar Quick Connect Fitting Service .
5 Remove the EVAP canister purge valve bracket bolt.
6 Remove the EVAP canister purge valve with bracket.
7 Remove the EVAP canister purge valve from the bracket.
8 Inspect for carbon release in the EVAP canister purge valve ports. If there is any loose carbon, replace the EVAP canister and any components necessary to remove the carbon particles.