: coolant temp sensor

08-13-04, 02:40 PM
Could you tell me where the coolant temp sensor is on my 96 deville? Also, my air conditioning quit today. When I hit auto, it immediatley goes to econ. I spent about $800 on it last year with a new compressor. Is there any self diagnosis I could do? I don't want to spend any more on her, she's bleed me dry, needs more everyday, and it's time to go onto a fresher Deville.
Thanks for your time,

08-13-04, 02:45 PM
Try search for post "bad temp sensor?".

With my experience, the last thing you want to do is to change coolant temp sensor. I waste 2 days to change it and problem wasn't there.

08-13-04, 03:50 PM
Holy Moses, what a mess to install. I'll pass. thanks for the advise on where to search. Now, can anyone answer the air cond. question?
Thanks, Rob

08-13-04, 03:55 PM
At fisrst, try to check any current and history codes in your computer. You can find on that forum how to do that.
Good luck.

08-13-04, 06:47 PM
Yes, check the error codes. Press "off" and "warmer" (passenger temp) until all the dash lights come on and write down any codes displayed on the DIC.

The A/C problem could be related to the coolant temp sensor. If the computer sees the coolant temp going too high, the first thing it does is shut off the A/C compressor. There might not be anything wrong with the A/C. Check those codes and work on the coolant temp problem first. If you really are overheating, it's serious. If it's a false reading, it could be as simple as a loose connector.

08-14-04, 12:22 AM
Before anything else, see if your computer displays a coolant temp sensor output using the DIC. Hit "info" until it displays "engine temperature". If it is not receiving a value, it will display "--".

Hopefully you've found the ECT sensor. A mechanic will change it for you for 20 bucks, probably. Just take the car there, say, "I need my ECT sensor, I've got it here, but you need to lift the car. Alldata says it's a 0.2 hour job." That's about what it is, maybe a little more.

Your compressor clutch is disabled when the ECT sensor malfunctions to protect the engine from overheating.

Why do you need to know where the sensor is, anyway?

08-14-04, 07:21 PM
I pulled these codesfrom the dash.
PC0171, PCO174, PC1520, AC1347.
I went to the trouble code page and found none of these codes. I was going to put on a coolant sensor because it is a cheap try. A mechanic suggested it.This car has been throwing check engine lights since I got it at 39k, it has 69now. The first time the check eng lght came on, I took it to caddy and $800 bucks a mass air flow sensor and an O2 sensor later, it didn't fix the problem. I banged heads with them and all they wanted to do is guess with my wallet.The emmission service warning comes on every time it starts. I gave another Caddy store a shot and they didn't fix it either. I bought a scanner. I would erase the codes and after about 5 miles or the first time I would step down hard, the check engine comes back on. It says low fuel pressure or something like that for both banks. It also says the same codes that had caddy replace mass and o2. Once or twice a month, the car would just stop. Usually after a highway drive. It starts right up but runs a little funky for a short while. I am done. My personal feeling is that the computer is bad. This car had a new block replaced byGM under warranty at 38,000. I don't think it has ever been right. Now the ac compressor isn't on and I'm so done spending money on it. I hoped at least the code would explain that to me but I can't find the meaning of that code. Please help if you can. Thanks, Rob

08-14-04, 09:20 PM
P0171 - Fuel Trim System Lean Bank 1
P0174 - Fuel Trim System Lean Bank 2
P1520 - Transmission Range Switch Circuit
B1347 - Very Low A/C Refrigerant Warning (1347 will disable A/C compressor)

08-14-04, 09:37 PM
Thanks for your help, but what do these codes mean? Anthing I can fix myself? Also, if this means anything, I get what id best described as a girgle for about a second coming from the area of the gas tank whenever I get to about 1st shift speed. It has been there for 30k miles.