Check Gas Cap Message
WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
The PCM sends a class 2 message to the driver information center (DIC) illuminating the Check Gas Cap message when any of the following occur:
- A malfunction in the EVAP system and a large leak test fails
- A malfunction in the EVAP system and a small leak test fails