Mazda Fuel Cap

Aug. 12, 2019

This bulletin applies to 2014-2019 Mazda6 vehicles. Some vehicles may exhibit the check engine light on with DTC P0456 stored in the PCM memory (EVAP system leak detected...very small leak).

The concern is most likely the result of the customer not getting the fuel cap completely closed after refueling.

Verify the concern and perform the MGSS diagnosis procedures for DTC P0456. If a leak is detected, repair according to MGSS online. If no leak is detected, the most probable cause is the fuel cap not completely sealed. Do not replace any parts without detecting a leak using MGSS diagnostics. Explain to the customer that if the fuel cap is turned less than 200 degrees (B) it is not sealed. If the fuel cap is turned between 200-360 degrees (C), it is sealed. If the fuel cap is turned 360 degrees or more it is sealed and a clicking noise (D) is heard.