07 No codes, lights flashing?

I have 2007 Equinox with flashing lights on dash, Allwheel Drive Off, Service Traction Control, Service Stibili Track, and ABS light. All lights come on at once for a few minutes then go off. When shop looks for codes they tell me No codes are stored. The Equinox runs fine so far. this happens a couple times a month. The truck has 57,000 miles. Has anyone had this problem?

Those messages would definitely cause some codes to be stored. They would still be retrievable even if the messages are not displayed at the time the vehicle is scanned if you took it to them shortly after the event occurred.

Furthermore, they need to have a scan tool that is able to retrieve Chassis (Cxxxx) codes in order for them to see the codes related to those messages. Most inexpensive code readers can only retrieve Powertrain (Pxxxx) codes. If this is what they used, I'd take your car to a different shop and never look back. They should be ashamed for attempting to retrieve those codes with a tool that is not capable of doing so.

Without knowing anything else, I'd suspect a fault in the ABS system. It could be something as simple as a bad wheel speed sensor or a bad connection at one of those sensors.

The shop that scaned my vehicle is the GM dealer i purchased it from new. The vehicle was flashing the messages when i droped it off that morning. The dealer said if no codes are stored they cannot fix whats not broken. I also suspect some kind of bad connection at one of the wheel sensors. I just do not want to start changing parts and wasting money.