Ian06GTO

For the past month ive been having problems with my temp gauge not working. It only did it from time to time and when it did it the car ran like crap and would be hard to restart. Now it does it all the time. I looked behind my glove box and all my wires are still wraped up and in good shape. I took it to the car to the dealership and they said that the coolent sensor was fine. Any one have this problem...

402GOAT

iTrader: (2)

a gto that i recently installed a cam in did this same thing while the tuner was working on it. coolant temp would go max hot. wiggled around on the connector going to the temp sensor and found that to be the problem. the wires inside were loose. bought a pigtail from gm and replaced it. be good ever since.

trbolssln0522

iTrader: (4)

What do you mean by not working? Does it register "C" and not move? I would hook up a scan tool and view the readings of the ECT sensor in either voltage or actual temperature and compare it to the readings on the dash. If it registers on the tool but not the dash, you can bet its something electrical in the dash area. If the tool registers 0 or -40 on the ECT then I would unplug the ECT sensor harness and backprobe the wires to check voltage. Remember that there are two wires, one (gray/black) which is your reference (you should see 5 volts with the key turned on). The other one (yellow) is the ect signal which is the feedback to the pcm. If your actual temp sensor is good (according to the dealer) then check the voltage coming out of the gray/black. Dirty or loose connections can be a cause as well. Cleaning out the terminal with some electrical cleaner then adding di-electric grease wouldn't be a bad idea. Good luck bud, keep us posted on what you find.

Ian06GTO

Yeah the temp gauge is suck on c and not moving at all and the a-c wont work and the electric fans stay on

trbolssln0522

iTrader: (4)

The fans turning on along with the a/c not working, is a default in which the PCM is not seeing the ECT sensor. Now assuming that your sensor is good (according to the dealer), take a volt meter and look for those 5 volts at the (gray/black) connector. Make sure the other terminal (yellow) is .10-.20 volts. If you do not see these voltages, or you see more on the yellow terminal you either have excessive resistance or a short. Let me know what you find. Dumb question, but did you check the harness for any cuts or burns? Remember that it is only inches away from your number 1 cylinder header tube. I have also seen an automatic transmission cooler line wear through this terminal before; extremely rare, but it could happen.

Ian06GTO

I replaced the ECT sensor and now everything is working fine. Insted of taking it to the dealer im just gonna come on here lol. Thanks for all the imput.

trbolssln0522

iTrader: (4)

Glad to hear bud. LOL what happened to dealer saying that the ECT sensor was fine? I would get your money back on the diagnosis if that was the case.

Ian06GTO

The dealer said that when they hooked up the tester they said that they got a good read on the sensor.......im guessing that the sensor was working when they tested it. They thought there was a problem with the harness.(Or just saying that) I have a powertrane warrenty and electrical is not coverd. So im glad that i could fix it myself.

massillongoat

iTrader: (3)

it was prolly and intermitten short we had this problem with a cam sensor...it would regsiter on the tech 2 with a signal but when you hit the key nothing...pulled the wire out of the loom found a bare wire replaced it fired right up no problem