“Speed Sensor” is a general term. A wheel speed sensor, transmission output speed sensor or a differential speed sensor can be used to calculate vehicle speed. The type of sensor used to determine vehicle speed can vary depending on vehicle application.
For a 1998 Buick:
I have tried driving without the cruise control. Just a hunch. Last 2 days on short trips 20 to 25 miles with a long break between it worked perfect. Today I drove for 70 miles with 50 on the freeway and with 2 fast stops and it worked just fine.
Not sure if just a coincidence.
Are you certain the brake lamp switch is working 100% correctly?
And I don’t just mean do the brake lamps work?
If the pcm receives a signal the brake lamp switch is actuated, that will definitely affect cruise control, afaik
The pcm wouldn’t know if your foot is stepping on the brake pedal. It would only know it’s receiving a signal the brake lamp switch is actuated . . . and it would take the appropriate action(s)
It wouldn’t be the first time a brake lamp switch is defective and causing weird problems without throwing codes and yet the brake lamps seem to be operating properly . . .
Didn’t you say you thought the VSS wasn’t plugged all the way in?? You need to drive it as normal to try to recreate the issue or to confirm the repair, don’t change it up after doing something, cause you have not confirmed yet if it was a loose connection that you corrected or not, you just added more what if’s…
To add to db’s point, you can have 2 switches on some vehicles, one for the brake lamps and one for the CC (basically), the CC switch could be failing but the brake lamp switch could be fine, or it could be a combo switch and part could be failing, remember (IIRC, brain fart) the TCC off command comes from the brake lamp side…They can also work together…
don’t know anything about any brake lame switch.
I did drive as normal after that and it didn’t change. At my view from that point, I was not sure if it was all the way in or not. It looked like maybe wasn’t. Can’t say for sure. if you ever tried simply getting the power steering cap off you know what I mean. Very little space to see from the top.
Today I drove again about 70 miles with a few short stops without using cruise. Worked just fine.
I don’t understand why that would cause it. But it looks like it should be easy to remove and the do a ohms test on it to see if bad.
If that was bad would the code have come up?
Symptoms of a bad brake light switch.
A failing brake lamp switch . . . especially if it’s intermittent . . . will often never result in fault codes, ABS warning indicators, etc.
Not according to your prior post..
You had said before that you were using the CC when the trans acted up, cause part of the symptoms were the CC stopped working… You need to drive it like NORMAL using the CC to see if it is still acting up or problem solved… You pushed on the VSS plug and may have corrected the issue, but until driven with the CC on, how will you know if the problem stopped or not???
