Transmission or electrical problem? [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: Transmission or electrical problem?


rogue449
11-03-2008, 12:12 AM
Hey Fellas,
My 2003 Chevy Duramax/Allison was running fine last week, then I added the Hypertech model #30029. I corrected the tire size for 285-75-16 's and put it on level 3. I went on a 120 mile trip to let the Allison learn and drove it easy, because my wife & kids were with me. When I started driving the next day all kinds of codes set.
P0700-TCM
U1800-lost communication with fuel injection control module
U2104-controller area network-bus reset counter overrun
U2106-powertrain control module
U2105-lost communication with engine control system
C0035-left front wheel speed sensor
C0040-right front wheel speed sensor
C0055-rear wheel speed sensor
P0380-glowplug
P0880-TCM power input signal
P0742-torque converter clutch-stuck on
P1093-fuel rail pressure low
The truck shifted hard from 1 to 2, normal from 2-3-4, and wouldn't shift to 5th until I ran it up to about 65 and let off the gas. I've put it back to stock settings, changed the fuel filter, the spin-on filter, and changed the trans. fluid even though it smelled normal. I change the spin-on every time I change the oil. It still shifts the same and sets the same codes.
I called Hypertech twice to see if they had heard of this before, but that was a waste of time. The local dealer checked and reflashed with factory settings. They said some of the parameters were completely blank. When they said leave it for a couple of days, I ran.
Truck is stock except tires, Hypertech programmer, and a tank of bio now and then.
Great site and thanks for any help in advance.

rogue449
11-04-2008, 09:28 PM
Anybody have any ideas?

Mike L.
11-04-2008, 10:49 PM
Broken wires in one of the harnesses. Or an act of God. Take your choice. Too many codes for a mechanical problem.

rogue449
11-08-2008, 10:32 PM
Mike L, thanks for answering

I've checked the electrical connections and looked over the wires, but haven't found anything wrong. Is there any way to narrow the problem down? Is there any way to test the TCM or the trucks computer?
Thanks