st205 plug in fitting new IAT sensor

[Adzn3k]

Hi guys,

I'm not sure what i'm doing wrong here but I've bought an ntc sensor like this one:

https://shop.vems.hu/catalog/sensor-p-115.html?osCsid=47f9a41f3c94d0a670a4ca5a81d7edaf

i've wired it up in place of the OEM sensor but i'm getting an intake temp of -40 I've selected the std bosch ntc table in the settings. any hint?

[Adamw]

The Bosch calibration is correct for that sensor.  -40 suggests the sensor or your wiring is open circuit.

Heres a couple of quick tests you can do:

On the temperature input you are using, set the error low to 0V and the error high to 5V, this will prevent these from confusing us.  Unplug the sensor, ecu should show -40°C.  Now short the two pins in the temp sensor plug together - use a paper clip or similar.  The ECU should show 150°C with them shorted together.  If you dont get 150deg when you do this test then your wiring is open circuit.  If you do get 150 then your wiring is correct and you can suspect the sensor is open circuit.

You can test the sensor with a multimeter.  At normal room temp (about 20degC) you should have 2000-3000ohms resistance between the two sensor pins. 

[Adzn3k]

Hi Adam,

I've just been out to investigate and I've worked it out, it turns out that the link is wired to take the IAT from the sensor that goes in to the factory air box not the one in the intake manifold. i have recently tidied up my loom and removed the stock sensor that is fitted to the factory airbox so when i plugged it all back in it caused me to have the issue i originally posted about.

The sensor in the intake manifold is wired to ANtemp 3.

The sensor in the factory airbox is wired to ANtemp 2.

So if these settings are not changed by the installer or tuner potentially they are mapping to IATs that are before the intercooler.  Which is what happened when my car was originally mapped and could have been very bad if I'd not come across this problem when i upgraded to the quicker sensor and binned the one in the airbox.