Jeep Compass is keep dying

[c@ctuz_]

Man, my dad's old 2018 Jeep Compass is acting totally whack and driving him nuts. (And, yeah, he's probably gonna blame me since I use it a lot.)
It just keeps dying, even after we've swapped out both the main battery and auxiliary battery.

He even had a mechanic put the aux one in. The thing will start up after some fussing, sometimes even drive fine for an hour, but then it's dead again the next morning.

The mechanic checked the alternator and says it's charging, but the car still won't start after sitting. He ran a scan and got these codes: PU562, U1428, and P1DD2.

He's telling us to go to the Jeep dealership, but I heard it could be something simple like a fuse.

Anyone got any ideas? This thing is killing us!

 

[TrueNorthMark]

It sounds like your dad's Compass is running into some typical aux battery problems. Even with a new main and aux battery, if the aux battery isn't the right AGM type or isn't fully charged, it could trigger those codes (U1428, P1DD2) and lead to the car dying or failing to start after being parked for a while. The alternator could be perfectly fine, but the aux battery is crucial since it powers the electronics when the car is off.

I'd recommend taking another look at that aux battery, sometimes, you really need a specific AGM type for it to work right. Also, consider getting a dealer update to clear those codes. It's less likely that fuses are the issue given what you're describing. Hope this helps

 

[dailytrailscout163]

Makes sense. Yeah, those error codes usually point to either a battery that's not up to snuff or a weak auxiliary battery. Making sure you get the right one and that it's fully charged is super important.