No, no. I ran the car for about 3 miles without the 10 amp in, and the temp gauge started to work. Plugged the 10 amp back in and now the fans and the gauges are working as they should.

 

Oh ok, gotcha. I think the same thing would have happened if you had taken the relays out and drove it. I still think one of the relays may be sticking, and it just unstuck when you took the fuse out and put it back in. Let us know when you find out what the problem is tho, especially me...lol

 

I have a 2001 6cyl camaro. The engine light came on, my water temp gauge went dead, and my fans kept running.
-I pulled the 10 amp gauge fuse, and tried to start the car. The car wouldn't start.
-I put the fuse back in, started the car, and the temp guage began working again, and the fans shut off. The engine light stayed on, but eventually went out.
Works for me. Thanks.

 

[quote=z28pete;395945]The gauge and the pcm use diffrent temp sensors, so the problems do not seem to be related.[quote]

This is NOT true of the 3.8L v6 engine. There is only one coolant sensor, which serves both of these purposes (telling the PCM the temp, and sending to the guage). It should have three wires. One goes to the PCM's "sensor ground" input. One goes to the PCM's "ECT Sensor" input. One goes to the temp guage in the dash.

Yes, the ECT sensor is above the water pump.

Your problem definitely sounds like an ECT problem. I believe that PCMs in the later years were programmed to turn the fans on full blast if they don't get a reading from the ECT (i.e. if the ECT isn't working, it turns the fans on to prevent overheating). If it was one of the relays, it wouldn't be affecting your guage.

 

If it was one of the relays sticking, and keeping the fans on high all the time, it most definately would affect the gauge reading. Whatever it is causing the fans to run on high all the time, whether it's a relay, fuse, ECT, or something else, would surely never let it warm up as it should, thus affecting the gauge.

 

I'd like to try bringing this thread back to life, if possible. My '02 V6 Camaro did the exact same thing-- fans on all the time, temp gauge quit, check engine light came on (low coolant temp code).

First I tried replacing the coolant temp sensor, but no change. When that didn't work, I searched online for other things to try and found this thread. Tried all of the suggestions: first removed the fan relays, tapped on them and re-installed, but no change; next I pulled the 10A fuse, let the car run for awhile (drove around the block), and right before I gave up on that test, the gauge suddenly went right back to center as described by xXOfNiRXx! Fans shut off, and the gauge works again.

I re-installed the fuse and all appears to be working right. Check engine light is still on, but I think it takes a little while to turn back off. The car will be tested further on a one hour commute tomorrow.

So, here are my questions:
1) Has anyone figured out what caused the original problem (i.e. why did pulling the fuse and running awhile work, guess something needed to be reset?)?

2) And, if any of the original posters who fixed this problem are reading this, did it ever come back? I ask because my temp gauge has been finicky for years. It has turned off before, especially during road trips, but always came back eventually. This time it didn't start working on its own and if there's some underlying issue I'd like to fix it.

Thanks!
Selena

 

To my experience with this problem it usually means the Coolant Temp Sensor (CTS) is faulty. This system uses one CTS for guage and PCM and the PCM controls the fans. As a failsafe percaution GM has the PCM set to turn fans on if no reading from the CTS is found.

Pulling the 10 amp fuse should not have assisted in this unless there was some corrosion on the contacts that was wiped clean from the removal and reinstall.

The gauge and stuf coming back on is the result of the PCM running a test on the CTS circuit and finding the CTS working or within acceptable parameters again. and allowing the signals to be processed again. This again points to corrosion on the contacts (at the CTS, fuse, or PCM) or a faulty CTS. The gauge gets its inputs from the PCM, not from the sensor directly.

Massey

 

Funny this thread should be revived. I just bought yet ANOTHER thermostat to put in and try to see if it solves this problem. So far I am on my 3rd CTS (surely 3 in a row can't be bad), and this will be my 3rd thermostat. The gauge will sometimes be functioning normally, and as I'm driving all of a sudden the gauge goes all the way to the left. Not slowly, but instantly, the fans will come on, and after a while the check engine light will come on. Then again it will be ok the next time I drive it.It currently isn't working, and hasn't worked for about a month now. I don't drive the car much, so it's not a big deal, just a heck of a nuisance not to be able to figure it out. All relays have been changed, and I can't see any problem with the related wiring anywhere. So if anyone ever does truly solve this problem, I'd love to hear it.

 

that's interesting, because my v6 did the same thing, then I watched overheat one day to see how hot it would get... it went just shy of 200, then the thermostat opened and it dropped below the temp reading...

Do you know what temp your thermostat is set at? it may be too low...

 

With the temp flying up really fast like that sounds to me like you need your system purged properly. The little screw on the T-stat housing will remove the air from the top of the engine. This needs to be done since the water in the engine is higher than the top of the radiator. If you allow the air to stay in there it will build up steam pressure and that will exceed the pressure that the waterpump generates so the water will not flow through the engine or radiator.

Massey