CTS (coolant temp sensor) charactoristics

[myclone]

Figured Id post this here first to save me some research as someone may know this right off the top of their head...

What are the charactoristics of the stock coolant temp sensor that is in the intake located beside the t stat? As in: Varies in resitance to ground for the ECM or does it drive the positive side? Im guessing since its a two wire sensor that it drives the positive side?.. Is it logic level 0-5VDC or supply level 0-12VDC that it works with?

For the curious Im working on a temp sensing thingy for a fellow sytyer that will use an adjustable comparitor to pull in a relay for the cooling fan that uses the signal off the CTS. This will allow him to adjust it easily for the track (fan on at colder temps) or for getting smogged (fan comes on at higher temps).

TIA

 

[jwaller]

the cts is a 0-5V sensor. that works by resistance. 190deg is normally 1.5-2.0V.

black is ground and the yellow is the 5volt referance. it shares the ground with the map sensor.

it ranges from
deg ohms
210 - 185
160 - 450
100 - 1800
070 - 3400
000 - 25,000
-40 - 100,700

 

[bigmellon]

What he said! The sensor just changes resistance as temp changes.

If you just want the fan to turn on, why not just tap into the fan control relay? Or better yet, add your own fan control relay and temp switch in paralell with the stock system.

Altering the engine temp input may throw off the ECU calibration...

 

[Lynn D. Brown]

Hey Guys,

I've got another Q on that :

It seems that the other T sensor (gauge) - down low on the block on the rear Drivers side is NLA from GM. It is of concern to me because I just put on ATR headers, and they interfere w the wire going to it.

ATR includes an extension to reroute this wire, but the plug only fits the CTS that we're talkin' 'bout here. So, I guess maybe that this substitutes for the old guage sensor ? But then the stock plug won't work - gotta give ATR a call.

 

[sytyguy]

Lynn...........GM may no longer carry that sensor (not sure why as it is mucho common), but the aftermarket still does - Standard PN TS253. Other than splicing in an extension into the harness yourself, I don't see any aftermarket extension offered to plug in

HTHs

Hood

 

[myclone]

Thanks for the specs waller.. Thats what I was after.

If you just want the fan to turn on, why not just tap into the fan control relay? Or better yet, add your own fan control relay and temp switch in paralell with the stock system.

First off last I checked there wasnt a relay installed on the stock serpintine belt and the purpose of this thread is because I am making my own fan control set up....

Altering the engine temp input may throw off the ECU calibration...

Not on my system it wont... Ive got enough gray matter to use a buffer with high impedence so it wont load down the CTS signal. The ECM will never know its there.