Need help with codes 2b55 and 2b26

Couple days ago I floored it from a standstill after the light turned green. The car stalled for a few seconds (felt like forever) then I was able to drive off. I didn't see any kind of warning light on my dash. Tonight I hooked up my laptop and these codes came up:
1) 2B55 SG internal monitor level 2
2) 2B26 Throttle valve monitor bank 2

Took it to the dealer yesterday and they were able to pull the same codes but had to stop there because they couldn't communicate with the DME to further troubleshoot. The SA also knew I had a tune so he didn't want to do anymore and risk voiding my warranty. He wasn't aware that before I brought it in I restored it back to factory software, sort of. I had it updated to 240e by a tuner and the GTS DCT was still installed.

So my questions are:
1) what do you make of the codes? ICV, throttle sensor, safe to drive?
2) why couldn't they communicate with my DME? Even though I could go back and forth with tune and factory software

Thanks for your help!

2B55 - P1602, Post-38
2B55 - P1681, Post-38
2B55 - P1689, Post-38
2B55 - P1691, Post-38
2B55 - P16B3, Post-38


2B26 - P155C, Post-44
2B26 - P155D, Post-44
2B26 - P155E, Post-44
2B26 - P155F, Post-44

regular guy wrote  

2B55 - P1602, Post-38
2B55 - P1681, Post-38
2B55 - P1689, Post-38
2B55 - P1691, Post-38
2B55 - P16B3, Post-38


2B26 - P155C, Post-44
2B26 - P155D, Post-44
2B26 - P155E, Post-44
2B26 - P155F, Post-44

B O O M

Actuator is bad, replace it and it will be ok.

Thanks Mike! What are your thoughts on why they said they couldn't communicate with the DME?