2010 Mazda CX-9 - Vehicle dies

my daughter driving after a stop light and car without any display lights dies. we cannot get it to duplicate. Battery and alternator are not the issue

Huh?? Could you explain the problem a LOT clearer than this?

Please explain how you know this.

While driving the car everything shuts off. No warning lights. However it did restart and we drove it home. Battery and alternator were checked at dealer. They cannot get it to duplicate and don’t find anything wrong

Maybe the ignition switch is bad. Does your keychain have lots of things on it besides keys?

Site did not get all my question. At stop light and turn green, when excellerating to turn corner car shuts everything off. However, it starts back up all by itself. Mechanic checked alternator and battery which were fine. Previous week there was a smell while driving. FOB for starting car so heavy key chain not an issue. Will have oil checked for coolant leak from faulty water pump. How about electrical or computer-mother board?

Do you mean this? Engine dies (which means lots of warning lights and tachometer goes to zero) and then it restarts by itself with no driver action at all? lights now go out.

“heavy key chain not an issue” ? humor us and remove the key chain. It could be the problem.

“faulty water pump” ? How do you know this? I don’t see how that could cause coolant to get into the oil, but this is a serious problem and should be addressed.

What kind of smell? Burnt plastic kind of smell?

Based on this, I’d guess you have a wire with burned insulation that is touching a ground when the engine shifts during a turn. I’d also suggest an engine mount has failed to allow this to happen. If the car has an automatic, start it, put it in drive, plant your foot hard on the brake and press lightly on the accelerator. The engine should move a little. If it moves a lot, or better yet dies and restarts, there is your problem.

Search the wiring loom starting with the battery cable to the starter for the burnt spot. Look where the clearance reduces or the wiring stretches when under load. Good Luck!