2002 Bravada Keeps Dying

Purchased a 2002 Bravada 2 months ago with only 43,000 km. It has been in the shop 4 times with the same problem and they have NO ANSWERS. It keeps shutting off while driving. The first couple of times it restarted after 10 minutes, the last couple of times it won't start and has been towed back to the dealership. We're heading on a road trip down through the states in a month and certainly need this fixed before we do. Any ideas?

More details - shutting off at any rpm or only at idle? What else happens at the same time if anything. Let us know ifany codes (SES light)?
Have to look at fuel pressure, electrical, and sensors based on your reply.

Here are more details - Vehicle just shuts off while driving, usually at 50 to 60 km/hr. No codes showing. The shop also hooked on a diagnostic recording device that stopped working after 2 days at which time they took it off, supposedly fixed it, hooked it back up and it ended up draining the battery and the vehicle again towed in. I'm hoping someone has a suggestion that I can give to the mechanic!

That is a tough one if a real time scanner can't find anything.
Low miles too. Well, at 5 years old I'd spend the $60 and put a new Delco or Standard cap and rotor on to rule them out - sounds like Canada so moisture/cold may have affected them. Then intermittent sensors (such as crank position) can do this but that scanner should have picked it up. Check the wiring down to the starter and the nuts and cables and see if all tight (stretch here but if you have a power drain). The fuel pump was tested but needs to be right after it stalls with a $35 tester at the fuel rail to ensure not a heating up press drop problem. The ignition module mounted with the coil may be going but on 96 up no shops I found have a tetser that connects right so its a replace and try at $75 so....if this goes the coil may not shut off and low voltage drain. Then could be a coil and at $25 easy to swap.
Hate to throw parts at it but sometimes thats only GM fix as the shop never sees the problem. Have you tried a GM dealer but they may do the same as I stated and charge lots - good luck and post back with fix or for more help as many of us go thru the same at some point!

The 2002 Bravada is coil on plug 4.2 straight 6, actually this thread should be in the Olds Bravada forum, anyway, ignition switches were problematic in those trucks and can cause this condition.

Just as a further note, it's at the GM dealership now and has been each time it happened for a week at a time. The extended warrantly was purchased, however, they've replaced nothing and that's why I've been seeking answers elsewhere...very frustrating. Thanks for all suggestions, I'll pass along to mechanic.

2002 Bravada is same as S-10 Blazer and 4.3L v6 isn't it?
2002 GM went to the larger Trailblazer 4.2 straight in addition to the Blazer but for a few years and added trailblazer badge to the 4.3 S-10 Blazer to confuse us all. They added a few others under GM brands same as the larger trailblazer but never an Olds model as I recall but I'm getting old!