The engine temperature gage reads low and my SES light is on. The friendly folks at Advance Auto Parts read error as "Coolant Temperature High or Low".

I plan to A: Replace the thermostat ... I think I can find it and I have done this before on other cars. Are there any pit-falls that I don't know about or is it a straight forward job?

Plan B: replace the coolant temperature sensor ... 'Zackly where is this puppy? I'm stumped! Can anyone give me a link to an illustration? As above; any pit-falls?

My ride: 2003 Blazer 2-door 4.3 ltr V-6 automatic.

Thanks!

 

I would first replace the thermostat. It may have failed in the open position. It's a straightforward job.

 

As said, the thermostat is easy. Pretty much the same as any other.

The coolant sensor is a $12 part located on the driver's side of the engine, just about dead center between the two rearmost spark plugs. You'll see it sticking straight out the side with a harness attached to it. There's just enough room to get one hand in there.

Be ready when you pull it out though, coolant will gush out.

**Edit: I knew I saw one somewhere.
http://i11.photobucket.com/albums/a1...T_Location.gif

 

Is the cooling system full? Do you get good hot air from your heater/defrost?

 

Thanks for the tips, Gents. And Kevets: Thanks for the link.

(Yep ... the coolant tank is full.)

 

Straight out of my photobucket account! I've posted it before which I am sure is how Kevets found it. But yep, that's it.

For some of the earlier years, there were two sensors, one in the bank 1 cylinder head and the other in the LIM right near the thermostat. The one in the cylinder head was for the gauges and the one near the thermostat was for the computer.

 

Thanks to all! I replaced the thermostat as suggested, dis-connected the battery for a while, and hey-presto! problem gone! The SES light is off and the engine temperature gage reads normal (mid-range.)

Problem solved! Thanks again.

 

Good deal! Thanks for the follow up!

 

Tip-- do not rely on the coolant tank being full. If you have a bad radiator cap the tank can be full but the radiator/engine can be low on coolant.

 

hey guys i have the exact same problem...the SES light came on, drove down to autozone to get the code, did a little research replaced the sensor and the thermostat...totalling $20...no biggie...and now a week or so later SES light comes on again and drove back to autozone and its the same code...low collant temp? any thoughts?

...also just to add the temp gauge never gets to operating temp...only gets just a notch or two above zero, but ever since the outside air temps have dropped its been like that, not the SES light, but just the gauge not getting up to normal temp...

..also if it matters...2004 ZR-2 4.3