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IAT sensor


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Hi Gents,

I’ve been going round in circles trying to find out why he IAT is slow to respond and always high. I pulled the sensor today and that is when I found it is an FAE one and was reading 28 degrees when ambient was 16-17.

To test, I blasted very cold compressed air on the sensor, it took a while to change to around 22, but then started to climb to about 23 again whilst cold compressed air was still blowing on it. When I stopped, it quickly climbed back to about 28/29 which I knew was not ambient.

I set to Bosch 017, ambient then showed 17, I went to my other car and checked, it’s outside temp sensor was showing 18 ambient, but the FAE one was outside in the cooler breeze so likely very close.

I went for the same drive as I did with the other setting, IAT’s showed 44% less and it was more responsive.  I did a few more tests, got a thermometer,  ensured the output of a hairdryer and low and high settings, the FAE sensor read within 1 degree of the thermometer when being heated at the same distance for the same amount of time.

i feel like the FAE one is within spec of the 017 Bosch sensor close to 1 degree on each test with the thermometer. To be sure I went to buy an 017 but can not find them anywhere. Whilst my tests were rather crude, upon changing the setting again after the sensor had cooled and was outside the car it again showed 17, if I changed to the original setting it would show 29, no way again was 29 degrees outside. Checked my other car outside temp sensor, it showed 18.

Does anyone have any other ideas for teasting, or where I can obtain the 017 sensor? Would you be happy that with the test I conducted the 1 degree difference is negligible? Certainly better than a 44% difference!








Edit, also FAE sensor showed 1.68 k ohm at 20 degrees 

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In the latest g4+ software help file there is a table of the common temp sensor resistance curves.  You could compare yours at 3 points - say ice water, boiling water and room temp to see if it is close to any of our built-in calibrations.

1.68K @ 20 definitely sounds like a 017 type.


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25 minutes ago, SteveX said:

Would the water damage it?

No, done it many times.  I suspect under some conditions they probably have a haze of fuel on them in the manifold so I dont think liquid will hurt them.  If you are worried you can put it in glad wrap or a latex glove finger etc.

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