Hi! I have a 2016 xc90 that occasionally doesn’t crank. I’ve replaced everything possible. The test shows not problems. As someone who has never worked on a car and runs a nonprofit for a living (so don’t judge me too hard), I feel like something is loose like a wire or sensor? Has anyone else experienced this? I can shut a door hard and it will start right up. It never dies and the auto shutoff when stopped always starts back up. It’s only when I turn the ****.

 

unfortunately, diagnosing intermittant failures can be very difficult even for a trained pro with all the tools. If you can replicate the problem (say first thing in the morning, after a long drive on a hot day etc) that will help provide some clues. You are probably right that is some loose connection so there's a place to start. You can check battery terminals, the battery cable to the starter, the ground strap etc. If the car won't turn over, what happens if you try to jump start? Next is to have a fully featured OBD2 scan tool to see if there's any fault codes stored. If there's a wonky computer or electronics module, it may report as a communications error. Not sure if you have a push button fob or a key to turn - but on older cars, a quick test for a faulty ignition switch is to wiggle the key while trying to start to see if that makes some contact happen. After that you'd need a shop who will start doing some electrical tests to see if any components are not getting voltage when the key turns on - suggesting wiring or a failed relay.

 

It has a **** on the console you turn to crank it. If it won’t crank, you can’t jump it. It’s something to do with that ****, I think.