For the past couple of weeks my Yukon has intermittent problems. -The speedometer will start out idling at 35-40 mph. The next time I start the car, it may be normal again.
-The Check Engine light will come on.
-The Service Stability light will come on.
None of the issues happen at the same time.
Any ideas?
They all relate. The likely culprit is a faulty vehicle speed sensor(VSS) which giving incorrect reading to speedometer, your stability control system and engine computer hence all the lights.
Get the code read and it likely will be related to VSS.
The same thing happened to my 03 avalance. There was a recall for that year on GM dash gage clusters. The servo motors that run the gauges were faulty. You had up to 50000 miles to take it in to get fixed. I’m sure it’s to late for you now but you can still get it done if you pay. Or do it yourself.