Stalling for a few seconds

I have a situation with a 2006 Canyon crew cab 2.8,automatic, 89,000 miles, bought new and no major issues that has stumped my local mechanics (who have a good record over the years BTW) and a GMC dealer. Several times lately on the highway it has cut out or stalled for a couple of seconds and then comes back when the accelerator is pressed.The tachometer falls and various red dash warning lights will come on or flash for a couple of seconds, but no check engine light.
In between several of these occurrences, there were two bouts of complete stalling which necessitated pulling over and restarting. This event had a check engine code which resulted in replacing the crank sensor. The other instances remain a mystery as the mechanics naturally couldn’t get the truck to repeat the problem. A service foreman at the dealer where I bought the vehicle had no clue either. Any help would be appreciated.

Several years ago a friends new car would stall unexpectedly and had trouble restarting. It took the dealer a while to figure out that one of the battery cables was bad and breaking / making connection randomly. New cables fixed it.

Another possibility is a clogged fuel filter. It’s been a while, but your symptoms sound similar to the ones I had with a car a few decades ago.

Have a lot of keys on the keychain? I am thinking ignition switch

1 Like

Thanks, mechanics say battery checks out

Supposedly has no fuel filter

Not a lot on key chain. Ignition does not seem to move, but of course GM had problems with some ignition switches, not this model, but who knows?

Try to narrow it down to either spark or fuel. Stalling is usually one or the other. First guess, it’s a spark problem. Ask your shop if they can provide you a method so you can verify the ignition system is working, for use next time it happens. They may be able to connect a voltage meter so you can visually observe proper power or not to the ignition module. If they won’t do this b/c they think it would present an unsafe condition for the owner, ask them to keep the car and one of the techs can drive it to and from home every day. Eventually it will happen and the tech will likely be able to figure out if it is spark or fuel. Driving with just a single key in the ignition switch is worth a try too.

Thanks. I’ll take yours and the others ideas to my techs.