I'm getting a P0128 CODE on my Trailblazer. It is caused by a defective temperature sensor or thermostat. Where are these items located?
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2005 Chevrolet Trailblazer
Question: Where is the thermostat located on a 2005 Chevrolet Trailblazer?
Answer #1MShaw August 25, 2012, 09:53Enthusiast
Firstly, it depends on your engine. You'll either have the 4.2L or the 5.3L; the most common is the 4.2L. the thermostat is located on the drivers side of the engine, just to the rear of the alternator, if memory serves correctly (I'm not looking this up or looking at that particular engine to pass on general info). The ECT (Engine Coolant Temperature) sensor is located directly above it. Unless you are having issues with overheating, the problem will likely be the sensor itself. It takes a little digging, so, as long as you are there, I'd recommend doing the thermostat just as a preventative measure; it's only a hose and three 10mm bolts (again, if memory serves). Most competent DYI's can probbly do this in an hour to an hour and a half.
ReplyJOEVASQ, August 25, 2012, 11:55Rookie
Thank you for your prompt response. I already removed the thermostat and I also found the sensor right next to the thermostat.
I found a video on YouTube that instructs you how to replace the thermostat. Thank you...from Joe Vasquez