97 Tahoe cruise control unexpected disengaging - SOLVED

[Tahoe97]

Hello forum friends. Back here with another issue with my 97 Tahoe 4x4 5.7. This weekend while crusing along at around 65 mph with my cruise control engaged, the gas pedal suddenly released from its holding position and the cruise control was no longer holding my speed. I was unable to re-engage the cruise until about 20 or 30 minutes later on the trip when I was able to set my speed and the cruise would hold. This engage followed by unexpected disengaging continued through the weekend and seems to be a new issue. I am assuming my Electro Motor Cruise Control module is failing but I suspect a brake pedal cruise disengage switch malfunction could also be the cause. Any guidance here is greatly appreciated. Pictures of the cruise control module are attached. Thanks

 

[Eman85]

Brake light switch is a lot cheaper. I'd try and hook a test light of some sort to the brake light circuit and monitor it when driving. A scan tool will show you that also if you have one that reads live data. Turn signal switches are known to fail also.

 

[Tahoe14]

@OR VietVet may know

 

[OR VietVet]

@Eman85 is on the right track. Start with the simplest source first. Even though modules fail, they hardly ever do unless they are exposed to extreme heat or water or mounting problems or filth or or or....The brake switch is inexpensive and a known intermittent source of cruise control problems. I would also inspect the throttle body area for linkage and cable problems.

 

[Tahoe97]

Thanks, I'll swap out the brake light switch first and see if that resolves it.

 

[Eman85]

The switch is a pain to swap, hooking a test light up is simple. On my K2500 I found a terminal by the fuse block that had brake lamp power, easy to access.

 

[Tahoe97]

My brake lights work fine so I suspect some component in that switch that turns off the cruise may be malfunctioning. We'll see.

 

[YukonGTmaster]

The Multifunction switch/Turn Signal stalk can cause a myriad of problems. Cruise control, turn signals stuck on, brake switch issues. Ask me how I know.

 

[exp500]

Cruise boxes also known failure items. But it's best to eliminate other possibilities first. They are a pretty much junkyard only item.

 

[Tahoe97]

I ordered Brake Light Switch ACD#1565E/GM#93801734 from Summit Racing with a new identical retainer clip from the Dorman GM Brake Light Switch Retainers 6 pack #13808 (Advanced Auto). It was a royal pain in the you know what to navigate tools, hand, switch, and retainer up above the steering column and remove the existing retainer clip and swap out the switches and install a new retainer clip. I managed to get it done, tested the brake lights and then took it on the highway to set the cruise which worked as designed. The test now comes over time to see if the cruise stays engaged on an extended drive. With 27 years and 238,000 miles on the original switch, the switch replacement may have been the solution. Thanks for the input!