Coolant Temperature too low? Check Engine light..

**gotacamaro** · 03-05-2009, 03:07 PM

Hey,

I have a 2003 silveardo 4x4 longbed.

the check engine lights keep coming on everyday after i reset it. Its throwing a code saying the coolant temperature went to low? or something like that, It is really cold out but obviously should not be throwing that code. Any ideas how to fix it?

I was told the truck may of had a new radiator put in it, could it be a sensor that wasnt property put back on?

thanks!

**Jimmiee** · 03-05-2009, 03:48 PM

How does your heater work? If your thermostat sticks open the coolant temp can bee too cool on cold days. Another possibility is there's air trapped in the system around the coolant temperature sensor. Or it just may have a bad connection at the temperature senso,r or just a plain old bad sensor. The best way to see what's going on is with a scanner.

**ct9a** · 03-05-2009, 04:20 PM

Originally Posted by Jimmiee

How does your heater work? If your thermostat sticks open the coolant temp can bee too cool on cold days. Another possibility is there's air trapped in the system around the coolant temperature sensor. Or it just may have a bad connection at the temperature senso,r or just a plain old bad sensor. The best way to see what's going on is with a scanner.

Ditto. Thermostat or air pocket. What code number is it kicking out?

**daddytech** · 03-06-2009, 10:31 PM

I would say it's air, try this from cold take off your cap, start the truck and keep adding coolant until it no longer bubbles up once the truck is running and the coolant level isn't going down any longer and just before the truck gets totally warm fill it to the very top and put the cap back on and see if that doesn't change things for you. Oh yeah and make sure your reservoir tank is full to the full cold line too that makes a difference also.

**lube70** · 03-13-2009, 01:38 PM

code should be a p0142, not able to reach operating temps in predetermined time. Thermostat is going bad. Also, flush the coolant. Dexcool ( older version ) is known to cause issues in past models.

Don

**trailshredder** · 03-13-2009, 01:45 PM

Shouldn't have been a sensor removed when the radiator was replaced. I would say and air pocket or more than likely a stuck open thermostat. There should be a cooling system bleeder screw on the top side of your cooling system somewhere. I think it is on the thermostat housing on my GP and truck. Crack it open once your coolant gauge is up a little and see if you get any air out. If thermostat is stuck open and you get a new one .... I would get OEM on this. Not all thermostats are created equal.