'03 2500hd No Start, Codes U1026 And U1041

[jd250r]

Have a 2003 GMC 2500HD 4x4. No start/crank. Only codes are U1026 and U1041. The truck will start if you jump the starter relay. About 4 months ago had the same issue. I tested all the grounds to the pcm, found no grounds on one connector. Found that the ground wire on the right rear of the engine had broken. I repaired the wire and the issue was solved. Now I have a similar issue. The dash and everything lights up. I hear the fuel pump kick on and the system will pressurize. If the starter relay is jumped, truck starts right up and runs perferct. I have tested the grounds at the pcm, all test good. Without out a good wiring diagram, Im at a stand still. The truck has been a farm truck all its life on dirt roads. Its has roughly 245k miles. Any advice on where to go from here? I have a Snap-on MT2500 Scanner. Thank you for your help.

[Lazher Ashour]

i own 2000 silverado 2500hd 4*4 the error code u1026 ATC loss of communication class 2

 

the car doesn't go or move on when i put the gear on D(moves only at the begging of starting the engine then stops) but it move back when i shift the gear to R.

 

Please help