1. Technical Service Bulletins

Resolving Hyundai EVAP Issue

Sept. 25, 2023
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Example of the previous air drain case 31035-2K500.
Example of the previous air drain case 31035-2K500.

Certain 2012-2016 Hyundai Veloster vehicles equipped with a 1.6L GDI engine may experience a check engine light with the following DTCs:

- P0455 (evaporative emission system large leak) 
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Example of the new air drain case 31035-B2500FFF.
Example of the new air drain case 31035-B2500FFF.

- P0456 (EVAP very small leak)

- P0449 (canister closed valve...CCV...restricted vent circuit)

- P0451 (fuel tank PSI sensor range performance)

There may be no drivability symptoms associated with these DTCs. Replace the Air Drain case (also referred to as canister vent filter). The previous air drain case is P/N 31035-2K500. The new and modified P/N is 31035-B2500FFF.

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Remove the fuel filler neck.
Remove the fuel filler neck.
Remove the fuel filler neck assembly. Remove the retaining clip from the air drain case using a flathead screwdriver. Pull the hose to remove the air drain case from the filler neck. Release the clamp using pliers and remove the air drain case.
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Remove the retaining clip (A) from the air drain case.
Remove the retaining clip (A) from the air drain case.
Install the new/improved air drain case. Reinstall all parts in reverse order. Connect the GDS and perform the Evap Leakage Test to ensure a result of No Leak Detected. This will confirm proper installation and that the original P0455 condition has been resolved. 
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Release the clamp ad remove the air drain case (C). Install the new P/N air drain case.
Release the clamp ad remove the air drain case (C). Install the new P/N air drain case.
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Pull the hose (B) in the direction of the arrow to remove the air drain case from the filler neck.
Pull the hose (B) in the direction of the arrow to remove the air drain case from the filler neck.
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