dealing with the dealer means they have to diag the car , and yes i know what you mean.
i could be wrong, and im no mechanic, but it just simply sounds like a faulty harness or sensor.
if you can grab onto the harness connector, wiggle it/disconnect and reconnect it. you never know..
and Kc!!!!!!! no excuse for not having a code reader!!!
if you have an android phone, grab the "torque pro" app in the app store, and grab a 10 dollar obd bluetooth connector from amazon! boom goes the dynamite!
i think its compatible with the Magical Fruit & Unicorn Company (iPhone) but I am not certain....

if its not, there maybe some apps in the apple store you can look into..
please keep us updated...
edit: heres a suggestion.
if you have th service manual, look in the section for the sensors. there may be a dig screen you can access on the head unit to test them!