I have a 2006 Monte Carlo with an Intermittent No Start Problem cranks fine
I get DTC's
PO102 Mass Air Circuit low
P1516 Electronic Throttle Mod VS TP Performance
P1682 Ignition Switch Fault
P2078 IMT Valve Sensor Circuit High
after working on it and getting it to start I clear the codes and get all the codes except the P2078, I cant figure it out, it just suddenly started on thursday.

 

Not sure, hope some one can help though.

 

Now my 06 wont even start only crank no spark and no DTC change I give in I'm gonna pay the dealer the $120 Diag fee and let my Extended Warranty pick up the tab

 

Yeah, if you're warrantied you have to take it to the dealer. There's no reason not to.

 

ok so after a weeks worth of minimal time diagnosing my monte I have found my 2 problems 1 the battery is too small for my car causing intermittent voltage spikes to sensors and 2 the one sensor it did fry the TPS 1 and 2 Sensor in the Throttle body new parts tomorrow wish me luck on the repair also anyone else have this problem and does anyone know how to relearn the throttle body

 

Good luck!

 

Sorry to hear about your Monte. What engine is it?