My SES light came on the other day and it turned out to be the thermostat sensor or whatever the P0128 code is. I was able to go buy the part from Advanced Auto Parts (or so I think) but for whatever reason I can't seem find where the piece is supposed to be going. I've got two pictures, one of the part I bought and one of my engine. If someone could tell me whether I even have the right part, and if so, direct me to which part of the engine I should be looking to put this new part in, it would be greatly apprieciated.

Thanks

http://home.comcast.net/~kanyewest/Picture_002.jpg


http://home.comcast.net/~kanyewest/Picture_001.jpg

 

Ehhh sorry for the huge pics. I'm not too tech savy and that's the best I can do.

 

P0128 - Coolant Temperature Below Regulating Threshold

This code could mean that the sensor itself is reading improperly, the coolant level is insufficient in the engine, or that the thermostat has failed in the open position. I wouldn't have suggested starting right off with replacing the ECT (engine coolant temp) sensor...

Here is a thread that may be of interest to you:

2002 4x4 Blazer Code P0128



BTW, I just linked to the pics you posted. We try to keep posted images below 640x480 to cut down on page load times.

 

Yes that is the correct part.

The sensor is located on the driver's side of the engine block, down near the spark plugs. The is a thin piece that branches off of the wire harness that you can follow down to the connector on the end of the sensor. You will need a deep well socket, I think its a 19mm. You should have the new one ready to go when you pulll the old one out because coolant will leak out when the existing one is removed.

 

I guess before I would go pulling the old sensor out, I would want to make sure that the sensor is at fault. Nothing like replacing a part only to find out that it wasn't at fault...

Does the truck warm up to normal operating temperature as displayed on the dash gauge?

 

The temp isn't at the 195 degrees or whatever it should be right in the middle. The temp sits a little lower around 170 degrees.

My SES light actually wasn't even on this morning when I went to try and get it inspected but I'm sure it will be back on in no time.

 

Sounds like a bad thermostat to me. If both the dash and the PCM are telling you it isn't warming up, chances are its the t-stat and not both of those sensors going wonky at the same time!