So my cruise control started acting funny a while back. While driving with the the cruise engaged it would shut off randomly, like I had touched the brake. Sometimes it would stay working for 100 miles and other times it would only work for a couple hundred feet before kicking back off.

The truck is an early 99 so I don't have the "CRUISE" light on the dash. Also the BPP switch recall has already been performed.

So I started doing to searching online and found a few things to check out and they are as follows.

I installed a jumper wire in place of the BPP sensor to bypass it and the cruise still didn't work.

Next I checked out the BPS switch that is mounted on the brake pedal arm and it appears to be working as it should (ie voltage present when brake pedal is pressed). Also all the brake lights work as they should, and do not get stuck on.

Parking brake pedal is all the way up and the brake light on the dash is not illuminated.

Next I pulled the steering wheel and checked the cruise buttons for their proper resistances and those checked out. I reinstalled the wheel and checked the button resistance at the plug at the base of the column. Next with the key in the ON position I checked the voltages at the plug at the base of the column and it had 7 volts going up to the steering wheel buttons, and then depending on the button pushed there is a varying voltages on the return wire. I traced the return wire all the way back to the GEM module and there were no issues I could find. I also checked voltage at the GEM module plug and they matched the plug at the base of the steering column.

I couldn't find any way to check the VSS sensor so I just replaced it. I didn't have any of the bad VSS symptoms, I just figured for 20 bucks it was worth a shot.

I felt I was out of options so I bought a new GEM on Ebay and installed it today. My cruise still does not work and I am at my wits end.

I have scanned the truck with my homeowner scanner and came up with no relevant codes. There are 2 codes due to the chip on the truck and that's all.

I found on another forum someone stating that there are inputs from the transmission that also control the cruise control. I haven't been able to find any decent wiring diagrams for my truck so can anyone offer any advice on what else I should be checking?

Or is my best bet to bite the bullet and buy AE so I can really get a good look at the modules on the truck and see what is going on?

Thanks for any advice,
Mike