I have a big code list

[Cajunwrench]

Hello to everyone! I have a 2006 GMC 2500 HD diesel. The check engine light came on with several codes. Did not notice any power problems but here is my book of codes.
P0647
p0646
p0206
p0207
p0208
p0507
p0506
p0650
p0299
p0234
p0191
p0087
p0088
p0615
p062C
p0502
p0540
u1096
p0340
p0341
p0335
p0336
p0016
p2610
p0168
2068
2067
160c
u0106
381
268
615
403
Several of them repeated. Im thinking electrical obviously but was curious has anyone else can across this type of situation. I do know what each code means just didn't write it. What would have caused all of these codes to spit out all at once. Any avenues or direction would be appreciated.
Thank you,

 

[ak diesel driver]

I'd clear them and see what comes back

 

[btfarm]

Well Cajunwrench, Welcome to The Truck Stop! :welcome3:

Why not fill out your signature by going to the 'Forum actions' tab above then 'edit profile' and find all that stuff on the left hand side. Tell us what you are driving and then we'll know what we are dealing with in the type of truck.
Then go above to the DTC tab and all those codes will be listed for you.
I'd clear what you have though as suggested and then see what comes up as you go along.
Keep us informed.