I have a 34 ft Georgie Boy Swinger with a 6.5 new Hummer Diesel engine pusher. The transmission is an L480E electronic shift. Having lots of problems with 4th and overdrive not shifting and not holding. I am Going through all the basics such as checking solenoids etc. Changed and flushed oil and the problem has increased. The trans shifted into fourth momentarily and then quit shifting to that gear. There are a few oddities that I have found. The power to the lockup solenoid is direct and on at all times when ignition is on. It is not attached to the brake switch and power is still there when brake pedal is depressed. Maybe there is a component in the (Transmission Control Module TCM) that allows for this. The fuel pump is mechanical so there is no electronics attached to it like a PCM. The TPS is visible on the pump. I have no idea where the TCM is situated and have looked in most places. I believe there has to be one somewhere or because it is the earlier version perhaps there was a different system. Does anyone know where the Shift Control Module may be located on that unit? I am getting real frustrated as we started out on three trips and never got anywhere having to turn back because it would shift into 4th on test drive and then completely quit. Thanks for any help
" The power to the lockup solenoid is direct and on at all times when ignition is on."
Most GM/Ford transmission solenoids have the + voltage applied at all times and the - voltage is controlled by the ECM. It is my understanding that it is easier to control - voltages with solid state devices.
Richard
95 Bounder 32H F53 460 2013 CRV Toad 2 Segways in Toad First brake job 1941 Hudson
Had a similar experience with my '91 dually, trans service shop worked with GM to finally determine torque converter problem. After market converter towed well.
