limp mode

[reflex]

Hi there, im from the uk & have been reading the forum since i bought my jeep, & sorry ive not said hello before. Purchased my 2006 jeep kj auto 2.8 crd renegade with 70k miles with full sevice history 6 months ago & really love it.
Went camping with the kids last week & on the way home about 1 mile from leaving the campsite i slowed to join a main road & the gearbox was in the wrong gear, as i pulled away overdrive was gone with the dreaded mil light, the car was in limp mode. Stopped the car & looked for anything obvious all fluids were fine & with no temperature problems i decided to make the 30 mile trip home doing my best to avoid stopping & starting to protect the g/box.
Checking the car, fuse no 5, 20amp tcm in the pcm is the only fuse that was blown, diagnostics code was u0146, also tested & swapped the transmition control relay, if i disconnect the tmc plug, the fcm plug the as well both ecm plugs as well as the speed sensors & assembly trans/solenoid/trs modules that go to the g/box then replace the fuse & with no key in ignition & connect the battery the fuse blows instantly, volts across battery is 12.8 all earths are good. have tracked the tcm5v+ from the pcm all the way round the engine looking for shorts im now up to the tcm plug having gone round the engine bay & cant find any problems there is only one other connection on this circuit A903 c117 has anyone else suffered this. Thanks for reading.

[glend]

The code refers to 'lost communications with central gateway' or a comms buss issue. Sounds like a short in the loom somewhere or a major component. I'd get an auto electrican to have a look. There was a few cases of wiring loom chaffthrough on top of the engube where the loom goes over the back of the engine but this sounds more major.

[reflex]

thanks for your reply, the fact that i have disconnected the major components & the fuse still blows rules rules them out? if the tcm fuse is blown this gatway fault would show as the tcm is maybe part of the gatway?. im happy to look into this if i had a clue where to look, i do know ill get mugged if i take it somewhere local to me for repair.