PO128 code

has anyone had this code. does anyone no where the coolant temp sensor is located 2003 chevy trailblazer feedback will help. Thanks

This refers to the engine running out of temp range, not the temp sensor necessarily, this is almost exclusively a bad thermostat. http://service.gm.com/gmspo/mode6/pdf/2003/2003file2.pdf

Thanks for the reply that what I thought it might be. thermo probally stuck open.

Did changing your tstat fix the problem? I'm showing a PO128 on my S10 and I just want to know if its the tstat or the temp sensor

Welcome to AF, usually not going to get an answer on a thread this old, but that code points to a T'stat. BTW you really are in the wrong forum also.

its the thermostat. change it and you;ll be ok.