Evaporative Emission Control System

Evaporative Emission (EVAP) System Troubleshooting

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  1. Disconnect the vacuum hose (A) from the EVAP canister (B) and connect a vacuum gauge (C) to the hose.

  1. Start the engine and let it idle.
    NOTE: Engine coolant temperature must be below 70°C (158°F).

Is there vacuum?

YES

- Inspect vacuum hose routing. If OK, replace the EVAP canister purge valve.

NO

- Go to step 3.


  1. Hold the engine at 3,000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on, then raise the engine speed to 3,000 rpm (min-1).

Is there vacuum?

YES

- Go to step 4.

NO

- Inspect vacuum hose routing. If OK, replace the EVAP canister purge valve.


  1. Turn the ignition switch OFF.
  2. Reconnect the vacuum hose to the EVAP canister.
  3. Remove the fuel fill cap.

  1. Disconnect the purge air hose (A) from the EVAP canister and connect a vacuum pressure gauge 0-100 mmHg (0-4 in.Hg) (B) to EVAP canister (C).

  1. Start the engine and raise speed to 3,000 rpm (min-1).

Does vacuum appear on gauge within 1 minute?

YES

- See EVAP two way valve test to complete. Evaporative emission controls are OK.

NO

- Replace the EVAP canister.