Cadillac Repair: Northstar engine running and idling too fast, intermittent fault, e mail

Question
Last winter my 99 Aurora with a Northstar engine started idling fast and running fast at times.  It would idle over 2000 rpm and would run at 40-45 mph with out pressing the accelerator.  Sometime, I could turn the engine off, and restart and the problem was gone.  Other times, that didn't stop the problem.  The dealer could not determine what was wrong.  The problem went away over the summer and only returned this past week as it got cold.  While at first it was intermittent, the last two days it has idled fast and run fast consistently.  It's been to the dealer on two or three occasions, but they've been unable to reproduce the problem or to figure out what is wrong.

Answer
IS or HAS the CHECK ENGINE light ever illuminated while driving the vehicle and or has any other lights illuminated or any messages from the message display center ?.

What work or diagnostics of ANYKIND WHAT-SO-EVER have been performed on the vehicle trying to fix this problem ?.


Sounds like an intermittent fault in the IDLE SPEED CONTROL MOTOR.


If you are mechanicaly inclined or know of someone who is, You will need a DIGITAL MULTIMETER, Simple electrical schematics, Test procedures and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture. I do not have a website so you will have to e-mail: onlineautohelp@msn.com in order to obtain the information.