SES light came on awhile back. I got the code checked today and it came up P0128. I realize this is a code for coolant thermostat (coolant temp below thermostate regulating temperature), but I'm not sure what needs to be done.

Let me know if there is more to the code and/or what needs to be done.

Thanks for your help!

 

This is typically a failed thermostat, but can be the ECT sensor. Does your dash gauge indicate the proper warm up temp? If it does, then I'd inspect the wiring for the ECT sensor and if that checks out, replace the sensor.

 

My dash gauge does have the correct temp. So would you suggest it being the thermostat itself or the ECT? By the way...what's the ECT sensor?

 

If your dash temp doesn't come up to around 200*F, then you have a failed thermostat.

ECT sensor == Engine Coolant Temperature sensor

 

Where exactly is that located on these vehicles? Mines a 2001 and I just got the same code, but temp goes up fine. \



Edit* Never mind, found one of your other post telling wher it is. Now if I can only get the parts store to know what I am talking about.

 

Nick, it should be on the top of your engine right in front of where the water outlet tube bolts on. Look for a connector with two wires on it (I think black & white).

 

Thanks I did some searching after the post and found it, but the auto parts lady has no clue how to find the part. I am checking with NAPA now to see if they know what it is.

 

Well one of the fastest SES fixes I ever had. At least, I think that fixed it, still have to either drive or cut bat power to reset the PCM so the light will go away, but was a fairly easy fix.

Thanks again Blazerforum!!