Does anybody know the resistance curves for our CLT and AIT sensors?

[bobafett]

Hey I am looking for the specs on the resistance curves for our stock coolant temperature sensors (the ones the ECU sees, not the fan switches) and our stock air intake temperature sensor.

I checked my shitty chilton, and didn't find it. Also checked my nice real FSM, and couldn't find it in there either.

If anybody knows these off the top of their head that would be great!

Thanks,
Chris

[2oodoor]

I think your acronyms are off but here you go:
IAT- intake air temp
32 degrees F- 5.0 Kohms to 5.2
140 degrees F- 500 ohm to 520
plus or miinus 10% is acceptable

ECT- coolant temp to ECU
32 degrees F 5.0 K ohms to 5.2
195 degrees F .2 K ohm to .4 K ohm
plus or minus 10% is acceptable

Both sensors also get reference voltage

[bobafett]

sorry about the acronyms. I am going to be installing my engine management soon and those are the acronyms they used so thats what's in my brain lol. The system uses GM sensors with the following specs:

70 degrees F: 3300 ohms
180 degrees F: 350 ohms

It looks like they do not match very closely. According to my chart for my TEC-GT, at 39 F there is supposed to be 7500 ohms, and at 68 F, there is supposed to be 3400 ohms.

Time to buy a 3/8 NPT tap. :)

Thanks for your help, where did you find those specs?

[2oodoor]

Those ranges were for an 89 model LXi
do you need say the ranges for 5th gen civic and 86 LXi?
yep using the GM sensors may solve that, specs from Snap on Vantage

[bobafett]

86 lxi specs would help if they differ at all. However even if they are different I suspect that they will not be close enough to allow me to use the stock sensors.

[bobafett]

Here is the chart for the GM sensors. :)



Temp, C | Temp, F | Resistance, ohms
-40 -40 100700
-18 0 25000
-7 19 13500
4 39 7500
20 68 3400
38 100 1800
70 158 450
100 212 185
110 230 133
120 248 102
140 284 62

[2oodoor]

the 92-95 Civic and 86 LXi are the same values !

[bobafett]

Good to know, thanks!

[2oodoor]

those GM values posted are for the ECT , the IAT are different

[bobafett]

hmm, what values do you show?

I am looking in the following PDF:
http://distributorless.com/products/tecgt.php
http://electromotive-inc.com/pdf_files/TEC-GT%20Users%20Guide.pdf

Page 93-95 (PDF pages 94-96)

They claim to use 3/8 NPT threaded 'GM Style' sensors. I suppose it is possible that their sensors are calibrated differently, but I do not see any advantage to doing this. It looks like a similar sensor body with different colored connector and a different material in the tip.

Either way it sounds like I will need to use their sensors as opposed to making the Honda stuff work.

[2oodoor]

Page 96, shows IAT GM 70F-3300 ohm then 180F-350 ohm
those not quite the same, but then I am wondering why they didn't go lower temp and why so high temp as 180F, that is some hot intake air... ahhh turbo
Maybe I read it wrong
Vantage says GM IAT res parameter are:
40F- 7500ohm
70F- 3400 ohm
100F- 1800 ohm
160F- 450 ohm