Hey folks!
First of all, great site. So glad I stumbled upon it. Hope I can get some help with my issue.
My cruise control, runs for 15-20 minutes and shuts off abruptly, won't come back on till I wait about 3-4 minutes, then I can reactivate it. But that will only last 5-10 minutes. It does run longer when it'* cooler outside...which leads me to believe it could be the unit(control module) that is at the firewall?
Am I am in the right area?
Thanks

IMO more likely in the unit in the interior arm assembly. It works on resistance and they wear. The unit against the firewall works off vacuum ad isn't heat sensitive. They usually don't come back to life either.

Thanks for the reply. Could you tell me where that would be? Doesn't the unit against the firewall have some electronics and the connection to the throttle?

Opps. I just noticed you have a 99. Sorry I thought it was an 89. It yours a DBW throttle. Really not so keen on all electronic Cruise. I'm going to move this to the Mechanical section for your model and hopefully a gearhead will chime in.

Any ideas anyone?

Possibly the stop light switch? I'm not up on the newer systems.

Thanks for the reply, but now that'* not it. If I touch my brake pedal to disengage under normal circumstances, it disengages but you barely notice the change. When it quits on it'* own, it as if the power was removed suddenly, you feel it disconnect and you can hear the gas pedal pop back. I am just wondering if the module that the throttle cable and a connector are hooked up to is all there is. It'* not a inexpensive item, would hate to replace it and find out there is another module or device.

Check the electrical hookup. Make sure it'* clean and dry. Is there any pattern to it cutting out? Hot, cold, after a long time, totally random, hitting bumps, etc. I would still check the switch. I know this write up covers the TCC solenoid switch, but the brake switch is right next to it. This switch will shut off the CC. https://www.gmforum.com/electrical-133/tcc-solenoid-switch-284972/

It does seem to follow a pattern of sorts. It happens in the afternoon when the car is hotter than in the morning. It will go for about 15-20 minutes before cutting out, then it will not re-engage for at least 7-8 minutes. Then it will work again for about 15 minutes and so on and so on from that point. Thermal issue?

Dan, thanks for the help and the link. I did the test for the switch, performs as it should. So i found some used modules online. Think I will try one of those and report back on the results.