: Where is water temp sending unit located?



ntechnic
09-02-05, 05:52 AM
After they replaced my defective battery today, my water temp will only read "---". All other readouts on the tach read just fine. So I'm thinking the dealer tech may have knocked a wire off the sender or something. I'd just as soon look for it as them.

Anyone know where it is? Or if any of it's wires are near the battery?

Barak
09-02-05, 11:39 AM
The check engine light should be on if the engine coolant temperature (ECT) sensor is disconnected. If the check engine light isn't on, then something may have gone wrong with the instrument cluster. Maybe one too many voltage spikes from changing the battery fried something in the cluster.

ntechnic
09-02-05, 12:38 PM
Thanks, I guess it's back to my dealer. The security system light keeps coming on at random now too. Sigh.

10secTy
12-17-07, 07:15 PM
What did this turn out to be? I am having the exacty same thing happen on my V.

thanks

Nolan

wildwhl
12-17-07, 09:56 PM
The temp sensor is just below the #1 spark plug, by the air box. Easy to knock off/damage the wires if you've done a CAI kit or pulled the stock airbox for any reason...and the result will be --- without any CEL (but you might have some other strange behaviors if the connection is intermittent!)

WW

10secTy
12-17-07, 11:04 PM
I hooked up my hptuners and can see the engine temps working find at the pcm. I can unplug it and see it drop to -30 on the scanner but the gauge reading stays at zero. I think my gauge cluster might have took a dump.
I need a Tech2 so I can hook up and test to make sure the gauge still sweeps.

Its funny because I was driving the car and saw the temp gauge just drop to zero all a sudden. I could see if I started it and it did not work. Seems funny it died driving along.

Nolan




The temp sensor is just below the #1 spark plug, by the air box. Easy to knock off/damage the wires if you've done a CAI kit or pulled the stock airbox for any reason...and the result will be --- without any CEL (but you might have some other strange behaviors if the connection is intermittent!)

WW

Black Sunshine
12-18-07, 04:36 AM
http://www.cadillacfaq.com/faq/answers/headers/16.jpg

trukk
12-18-07, 11:23 AM
http://www.cadillacfaq.com/faq/answers/headers/16.jpg

Imaginary points to you for posting a pic. GOOD SHOW!

-Chris

z06bigbird
12-18-07, 11:57 AM
My car does not have that green circular wire on it!!

LOL

Late Apex
04-26-13, 02:36 AM
This just happened to me today, and i'm a tad stumped at what is actually/or has actually failed if anything? Intermittently the temp gauge @ KOEO with door open or if the vehicle was off for a short time would operate normally for 10-15 seconds then the physical gauge and digital gauge will fall off and stop reading temp. Anyone with any insight or has delt with this and has a resolution to the issue I would greatly appreciate it. It really irks me to not be able to track/see coolant temp.

Silencertk
04-26-13, 05:35 AM
My temp sending unit went out couple of days ago as well. No gauge no digital temp readout. And engine hot - ac off message. Disconnected the battery, wiggled the wires tried everything. Went looking for a new sending unit - the car stayed parked for 2 days.... what do you know - started working again.

May not apply to you - but if its not your daily driver - let it sit for a day or two. And see what happens.

darkman
04-26-13, 07:04 AM
Intermittent readings from engine-related gauges are often caused by oxidation of the engine harness-related grounds. This oxidation is not readily apparent because it does not look like the corrosion that can develop on battery terminals. The fix is to pull the grounds and freshen them with some abrasive material - star washers can also help.

The critical grounds on the CTS-V include: the negative battery terminal; the ground located just beneath the hood stick mount; the ground located on the back of the passenger-side cylinder head; and the two grounds located on the back of the driver's-side cylinder head. If you keep these ground s fresh, you can avoid "ghosts" in your gauges. (This actually applies to most modern computer controlled cars.)

See attached.