Diagnostic Aids
An intermittent may be caused by a cracked or punctured EVAP canister, damaged or disconnected vacuum, vent or purge line. Check for poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Monitor FUEL TANK VACUUM display while moving EVAP connections and related harnesses. Change in scan tool display will indicate area of fault. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.