Evaporative Emissions System: Testing and Inspection

Evaporative Emission System Leak Test





Phase 1 - Leak Verification

1. Run the EVAP Test with the scan tool.

2. NOTE: Some small leaks may not be detected using the EVAP Test. If the system has passed the test but a leak is still suspected, then proceed to Phase 2.

If the Evaporative Emission (EVAP) system failed the EVAP Test, then proceed to Phase 2.

Phase 2 - System Leak Check

NOTE: Some vehicles utilize a conventional fuel tank filler pipe cap and filler pipe assembly, and some vehicles utilize an Easy Fuel (TM) (capless) fuel tank filler pipe assembly.

All vehicles

1. Disconnect the upper vapor tube-to-EVAP canister purge valve quick connect coupling. For additional information, refer to Fuel Delivery and Air Induction.

2. Connect the VACUTEC Smoke Machine Fuel Evaporative Emission System Tester to the upper EVAP canister purge valve fitting. For additional information, refer to the manufacturer's instructions.

3. NOTE: The battery ground cable was previously disconnected in the vapor tube quick connect coupling procedure.

Connect the battery ground cable.

4. NOTE: In the scan tool, the EVAP canister purge valve is referred to as the EVAP vapor management valve.

Open the EVAP canister purge valve with the scan tool.

5. Close the canister vent solenoid with the scan tool.

Vehicles equipped with a fuel tank filler pipe cap

6. Carefully turn the fuel tank filler pipe cap counterclockwise until the thread disengages and position aside.

Vehicles equipped with a capless fuel tank filler pipe assembly

7. NOTE: The supplemental refueling adapter is located in the jack storage compartment.

Install the supplemental refueling adapter into the Easy Fuel (TM) (capless) fuel tank filler pipe assembly.

All vehicles

8. NOTE: If smoke does not exit the fuel tank filler pipe neck area after the system is pressurized, open the canister vent solenoid with the scan tool to allow the air to purge. Once smoke is seen at the canister vent solenoid, close the canister vent solenoid with the scan tool.

Introduce smoke from the VACUTEC Smoke Machine Fuel Evaporative Emission System Tester into the EVAP system and verify that smoke is exiting the fuel tank filler pipe neck area. For additional information, refer to the manufacturer's instructions.

Vehicles equipped with a fuel tank filler pipe cap

9. Install the fuel tank filler cap once smoke is observed exiting the fuel tank filler pipe neck area.

Vehicles equipped with a capless fuel tank filler pipe assembly

10. Remove the supplemental refueling adapter once smoke is observed exiting the fuel tank filler pipe neck area.

All vehicles

11. Continue to enter smoke into the system for 60 seconds to obtain pressure.

12. Press and release the remote start button in intervals of 15 seconds ON and 15 seconds OFF while checking for exiting smoke.

13. Use the halogen light provided with the VACUTEC Smoke Machine Fuel Evaporative Emission System Tester to follow the EVAP system path and look for smoke exiting at the source of the leak(s).

14. Repair any leaks as necessary.

15. Repeat the leak test until the system passes.