E4 was the most recent one which means that it doesn't like that the pressure change per unit time - the compressor is assuming the hose got disconnected and shuts the compressor off. You hold the button to reset then press again to start inflating. But the error comes back.

The prior air compressor just stopped working and the display looked like hieroglyphics.

 

I really like the looks of the onboard compressor and was very tempted to get it, but decided to go with one of these instead: https://www.milwaukeetool.com/Products/2848-20

It actually has slightly more CFM than the onboard compressor and uses the same Milwaukee batteries I have tons of around the house. Similar features too including pressure memory, auto shutoff, etc. It's $169 or so for just the tool if you already have batteries for other Milwaukee stuff. Fits easily under the load panel - esp if you don't have the hybrid.

 

FWIW, my built in compressor was dodgy in 2021 or 2022 when I got it . Had the software updated, have used it a lot since then, zero issues.

Yes, if the hose blows off your tire I get E4 error (pressure mismatch), but you just restart it and works fine.