deepfriedbutter Posted May 2, 2023 Report Share Posted May 2, 2023 I have installed an IAT sensor I purchased off a vendor for ST205 IAT in the manifold. It is on AN Temp 3. The only information provided by the vendor is: NTC type sensing element (Negative Temperature Coefficient means that resistance falls when temperature rises)appr 2252 Ohm at 25C (same or very close to the sensors used by automotive manufacturerssuch as BoschGMVAG). 2252 table (and aref=256) is a good starting point. Using CAL Table 1, I have tried inputing resistance and temperature values from different sensors without any luck -- the readings are way off and none of the included calibration files match or are event close to ECT at dead cold. The closest table I could find is below the graph here (link). The Std Bosch NTC looks close but still off by quite a bit. The vendor did not provide any part numbers, but after scouring the internet this is the sensor in question: https://www.emiauto.eu/en/home/1037-genuine-bmw-temperature-sensor-air-11613449116.html Quote Link to comment Share on other sites More sharing options...
Vaughan Posted May 2, 2023 Report Share Posted May 2, 2023 Might match up to the Link NTC12 & IATB calibration Which is actually the same as our std bosch calibration You can create a calibration for it by immersing it in boiling water and taking resistance readings alongside thermometer readings as it cools down Quote Link to comment Share on other sites More sharing options...
Adamw Posted May 3, 2023 Report Share Posted May 3, 2023 Denso efi was mostly all licenced Bosch stuff and almost all Japanese cars from this era used the "Std Bosch NTC" curve (2500ohm @ 20°C). So Im 99% sure your original sensor would have used the Std Bosch NTC calibration. Their claim that it is "same or very close to manufacturers such as GM" suggests they have no clue, GM use the Delphi curve which is around 3500ohm at 20°C. The diesel sensor in your last link is quite a rare one and I have never seen it used in a Japanese vehicle by the OEM (commonly fitted to GTR's in the aftermarket tho, as it is the only fast response sensor long enough reach through the long boss). BMW, Landrover and Fiat use it (mostly diesels) the calibration for this is listed as "Hella 6PT 009 109 041" in our software. This sensor is 6600ohms at 20°C, so again a long way off what they are claiming. Have you got a multimeter to confirm its room temp resistance?. Quote Link to comment Share on other sites More sharing options...
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