[apk919]

Originally Posted by ocelot27

Call me a tart but I looked at that PDF and it seems to only describe the thermistor part (two leads) but there are four leads going into the housing of the IAT (Bosch part# 0 261 230 042). I would take my multimeter to it but there's no good access to the leads because of the environmental seals - can you simply tell me which colors are what? Or simply which lead provides the variable voltage from the thermistor? Also what's the most convenient source of +12v (ignition on) to tell the fan controller when the ignition/engine's on and off - my guess is that one of the leads going into the IAT is +12V? - TIA - john.

here's the image from my engine:

From the '08 MY schematic:

You're looking at the TMAP Sensor...
Yellow (Y) is ground
Brown/Green (NG) is the temp signal
Slate (S) is MAP +5V
Orange/Green (OG) is MAP signal

Originally Posted by Mag

TC4_2 is ambient for air temps flowing thru the IC core. But can also assume air temps pre air intake are similar.

Air Intake -> SC -> IC -> Engine
So
TC4_3 is just before IC
IAT is just after IC which goes straight to intake manifold...
Both post SC temps.

If I'm reading the schematic correctly, IAT is taken from the TMAF sensor, which would put it pre-SC. The temperature signal from the TMAP sensor (post-IC) is not used...