2003 trouble code

[cold gin]

i went to advance auto today and had my 03 scanned for the service engine light was on...they told me the coolant temperature sensor is below temperature regulation...anybody had this problem?the temp gauge is reading normal...buddy of mine said to change the thermo stat...thanks

[maxwedge]

Welcome to AF, always post the code for better responses, but generally the t'stat would cause this.

[debkev]

I have the same thing going on with my 03 TB... I got a new t-stat and will change it out tonight. Looks like fun!! I just wish that folks would post their fixes to the threads they started. It would help out with redundant posts on similiar problems!!! Maxwedge...Thank you for all your responses...appreciate your answers and help here.

[debkev]

So much for changing the t-stat out tonight!! Gonna have to wait till the weekend when I can make time for it! Is there a post on how to do this?? Just from looking..I think I will need to remove the alternator and a few brackets and other stuff just to get to it. 135,000 miles and this is so far all I had to do,other then a battery two yrs. ago.Can't complain..so far. THe code I got is p0128...

[maxwedge]

That is the T' stat code as a rule, check the info at autozone.com repair guides.

[debkev]

Changed the t-stat out..a 2 weeks ago.. light out and staying out. I found for myself that by removing the belt, alternator,the bracket just behind it and lowering the pwr.steering pump ,made it easy to get to the two bolts for the t-stat. Took a first timer approx. 1 hr. from start to finish. Thanks for the help here!

[duke316]

I pulled the same code off of mine. (coolant temp sensor). My question is would this cause the engine to die out at stops during stop and go driving?

[maxwedge]

No it will not, try cleaning the throttle body first.

[cdc692003]

po128 is engine coolant temp sensor and yes it can.

[maxwedge]

The pcm looks at air intake temp and other inputs and when they do not agree such as a thermo stuck open it commands a default setting for idle and mixture to prevent overly rich mixtures and stalling. This is on later obd11 enhanced engines.