psycho1

iTrader: (4)

I have a 03 GMC Sierra 1500HD the trans shifts real hard between 1st and 2nd but fine after that. My buddy used efi live to look at it and it's commanding max line pressure for some reason. It did have this issue for a while and did blow the last trans so I swapped it and still the same issue. There was multiple codes that came up on the truck and most were communication codes. The codes were u1000, p0748, b2600, b2610, p1875, u1305, u1016, u1096, u1301, c0327, b1001, b1007, u1016, b0424. There was 2 pages on the laptop with duplicates of these codes. I hear something about the grounds being bad so I will start there and see if it helps.

psycho1

iTrader: (4)

SO I disconnected the battery for a while today while I cleaned up the grounds under the drivers side on the frame. I then connected everything back went for a drive seemed ok and shifts were not to bad. Then I parked it again let it sit to see if radio stations would rest and they did. I then went to start it and nothing no crank just security light and seat belt light stayed on even with key out. I then disoconnected battery agin thinking maybe I didn't have it right or just something stupid. Everything is tight on the battery so I put the key in turn to on and hit the keyless entry lock and in lock a few times BAM it starts. Then the check engine light came on and reduced engine power popped up. So I checked the code it was p1518 so I reset it and it drove ok again still had the rough shift but not neck breaking like before.

psycho1

iTrader: (4)

When I can I will start adding some better grounds and check the TB wiring cause that was changed before I got the truck. Also battery is not even a year old so no low voltage like some of the searches say.