I thought I had just ran the battery down. I charged battery and it drove fine. The coolant level came on but did not run hot. A few days of not driving, it would not start again. This time, it won't start when battery jumped. Battery checked and good. Lights and dash work.
Diagnostic code shows nothing. It clicks a time or two then shows low battery on screen. The charger shows it went from 100% to 70%.

When put battery back on vehicle, the vehicle started immediately. It worked for about a week then when I stopped at gas station, it would not start again. It was showing restricted performance on the dash. It did seem to be flashing every message rapidly. And ideas? Any assistance would be greatly appreciated!!

 

You need to get the fault codes read. If it wouldn't start until you put a charged battery on it you should also check the earth lead connection.

 

Sounds like an intermittent bad ground somewhere.

 

Another option to have checked is the Alternator but this issue can be tricky: First just have a normal load function to make sure it is providing charge. With that said there can be a condition that is very difficult to detect that the alternator basically creates a dead short in a position that can drain the battery or cause a low voltage error that will keep the vehicle from starting. This is unlikely and rare but another possibility.

Bad grounding can also create bad charging and/or a low voltage state when trying to start as the ground cannot conduct power well enough to keep up with the starter power draw.

A faulty battery coil/plate (broken inside the battery) can also make an intermittent power issue that works fine when the plate "bounces" into position but can drop voltage or even discharge when out of proper position. Also rare but it happens.