: Coolant Temperature Sensor

01-06-13, 01:20 PM
Hey guys,

So I flushed the cooling system over the last couple of days, and everything seemed to be going well, got the car started, and the temperature was rising, all seemed well. Then the Radiator Fans came on, so I thought it was up to temp. Get in the car and look the temp gauge is showing all the way at the bottom. And the check engine light came on. Wondering if I possibly bumped the temp sensor when replacing some hoses. Does anyone know where it is located? I'll continue my search in the garage.

Thank you,


01-06-13, 01:49 PM
Most likely air trapped in the cooling system.

01-06-13, 04:21 PM
Most likely air trapped in the cooling system.

This is what I believe it to be. I let the car sit for a while, went back out and started it, and the sensor was working fine. I had the code cleared at autozone, and will drive it for a while to see if it comes back on.

Thanks for the response KRSTS.

01-08-13, 11:37 AM
I have the same problem (I think). Check engine light comes on when driving in traffic but will clear when driving highways. I had the radiator flushed and filled but it doesn't seem to have helped. How do I check for air in the system, Any insight(s)?
PS. 2007 STS4 6cyl w/105k miles.

Cadillac Cust Svc
01-08-13, 04:02 PM
I'm sorry to hear that, 2007sts4! Did you have the radioator flushed, etc., at a dealership? I'm happy to look into this matter further for you if you like. Please don't hesitate to email me at Katie_Lucille@gmexpert.com for further assistance.

Cadillac Customer Service