I am a working ASE certified mechanic (certified in everything but transmissions) and I have a Silverado in the shop right now with the same codes you have plus a P0161. Actually the P1406 (EGR code) went away after I exercised the EGR with a test tool and sprayed it out with PB, a penetrating spray lubricant.
The P0700 is a general trans control module failure that doesn't appear to affect the MIL.
I also have the P1192 code, which also doesn't affect the MIL, and for which I haven't been able to find a specific definition. One source listed it as Intake Air Duct Sensor High but other charts aren't listing this code at all so I'm still researching this code.
If I find anything specific I will list it here.
Wednesday, July 14th, 2010 AT 4:18 PM