download the pin outs for the ECU here
that is looking into the ECU, or the back of the car's plugs.
Lets see if I can explain this... (I suck at explaining thigns like this, so forgive me) With the car off, and key out of the ignition.
Grab a metal paperclip and unbend it, then gently push it till it stops into C15 and set the meter to Ohms. Unplug the connector on the IAT and touch one probe of the meter to the Red/Yel's pin and the other probe to the paper clip. there should be 0 ohms or really close to it.
Do the same for the Grn/wht wire and C22 on the ECU.
If either of them read O.L. or open or lots of M ohms then double check your paper clip first. If you can't get any connnection... then there is the problem.