PO128 code

[dansouth]

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

[maxwedge]

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/pd.../2003file2.pdf

[dansouth]

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

[ewoody625]

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

[maxwedge]

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.

[rubberman]

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