2006 Buick Lucerne randomly turns off

[3.8fan]

car turns off while driving or stopped
My 2006 Buick Lucerne 3.8 turns off sometimes while driving or when stopped. It turns off and then I put it in park or neutral and then it turns back on instantly like nothing happened? I’m not sure what it is or could be since it hasn’t come up with any codes for anything either.

 

[2007LucerneCXL]

Intermittent is a guess. Have you done a professional scan and checked for stored codes as not every problem with tick the CEL. Alternator, fuel pump or fuel, ICM are all best guessing on what to maybe look at. The 06 doesn't have the rear seat fuse box problem.

 

[3.8fan]

Intermittent is a guess. Have you done a professional scan and checked for stored codes as not every problem with tick the CEL. Alternator, fuel pump or fuel, ICM are all best guessing on what to maybe look at. The 06 doesn't have the rear seat fuse box problem.

Yea I’ve replaced the ICM before and the alternator is also about 20,000 miles old so it should be fine. I haven’t checked the fuel pump but every time I turn the power on without the engine the pump seems to turn on and sound fine. Also it’s seems that when I start the car cold it works fine but then when I park somewhere and come back maybe an hour later, it seems to start fine and the just randomly shut off. This happened today and it took about 2 minutes untill it let me turn it back on

 

[HotZ28]

What brand was the ICM you replaced & where did you purchase it? Have you even considered the MAF being the culprit? With no codes, this is a part changing nightmare, that can be very frustrating & expensive trying to resolve.

 

[RD_Atlanta]

A really easy test you could try is to wiggle each wire (one at a time) on the ICM connector while the car is idling to see if one has poor connection and causes the engine to die.