I have a 1998 tahoe and my speedometer and tac quit working and the trans. feels like its in safe mode i also pulled codes p0740, p0753,p0758, p0785, and p1860 but i was told that i could be all the solenoids and then i was told the computer could be bad and now i was told by another guy that its electrical could anybody please help any info would be greatly appriciated thank you

 

I dont know the codes off hand, but there are sights out there that have a whole listing of all codes, for that matter your dealership can print one out for you. If you trany is in "limp" mode you shouldnt be able to drive above 50mph normally. If the electirc solonids went out, would be in limp in mode-or stuck in one gear--sometimes two gears at once. If it is elecrtical problem in the tranny, thats also got to do with the solonids. Just to assure yourself before you take it in or do anything major, just go have a look and check all the wires are pluged in--not stretched--and i would also un-plug them and check for corrosion (common problem on t-cases thats over looked) on all connections going to the tranny.