Diagnostic Aids

Although this DTC is considered a type. A diagnostic, it acts like a type B diagnostic under certain conditions. Whenever this diagnostic reports the system has passed, or if the battery is disconnected, the diagnostic must fail twice before setting a DTC. The initial failure is not reported to the diagnostic executive or displayed on a scan tool. A passing system always reports to the diagnostic executive immediately.

Check for the following conditions:

• Missing or damaged fuel cap.
• Missing or damaged O-rings at fuel vapor and EVAP purge line canister fittings.
• Cracked or punctured EVAP canister.
• Damaged source vacuum line, EVAP purge line, EVAP vent hose or fuel tank vapor line.
• Poor connection at the ECM. Inspect the harness 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 to the EVAP vent solenoid, EVAP canister purge valve, and the fuel tank pressure sensor for an intermittent open or short circuit.
• Kinked, pinched or plugged vacuum source, EVAP purge, or fuel tank vapor line. Verify that the lines are not restricted.