99 Regal has ABS light & Check Light on together randomly.

My ABS and Check Engine and Traction control lights come on randomly but always together. I noticed that they come on at highway speeds above 70mph every time as well. I have seen posts regarding similar problems and
was hoping someone would pass along their wisdom experience that led to a solution. If you had it diagnosed, what was the prognosis?
Thanks in advance.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
It is all just a big fat guess until you have the computer read out and determine the codes. Then we can make an educated guess.....

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I have a 2000 Monte Carlo SS with 54,000 miles that is currently at the dealer with similar problems. They have had it for a total of 7 days over the last 2 months. It started with 3 warning lights coming on at different times, but progressively got to the point last week where 5 warning lights would come on for 5 seconds whenever the turn signal was used. Also, it started having unpredictable starting problems. Previously, the diagnostic test couldn't find a problem and the dealer said they couldn't do anything. This time the diagnostics showed over 20 error messages. The dealer says that their GM database says that replacing the ignition switch has solved the problem on some occasions. I hope so since I just authorized the repairs and am fed up with the problem and GM's crappy service and attitude.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.