Diagnostic Aids

Although this DTC is considered a type A diagnostic (refer to "Engine Control Module"), 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:

1. Poor connection at ECM. Inspect harness connectors for the following conditions:
   • Backed-out terminals
   • Improper mating
   • Broken locks
   • Improperly formed
   • Damaged terminals
   • Poor terminal-to-wire connection
2. Damaged harness. Inspect the wiring harness to the EVAP emission vent solenoid and the fuel tank pressure sensor for an intermittent open or short circuit.
3. Kinked, pinched, or plugged vent hose. Verify that the vent hose between the canister and the EVAP emission vent solenoid is not restricted.