We have a Thomas Bus year 2003. With Cummins Engine = Cummins ISB Serial # 46253187 The transmission is Allison AD2000. It was on a trip and the battery died. They jump started it with 24volts instead of 12volts. The transmission since then is stuck on 3rd (or it seems to be 3rd gear). We are in Mauritania (Africa). Any help on this would be appreciated. I am really not comfortable letting someone fool around with the transmission here. Thank you
Many electrical issues like headlights not responding etc have happened but all changed and fixed. The only thing remaining is the shifting problem. we have disconnected the batteries for weeks and on again same thing. You don"t think the 24volts could have affected the body valve on fried the wire harness to the transmission? Thank you both for your replies.
The TCM should be on the frame rail close to transmission and front axle, if it is same as in U.S.A.... I would be sure to check the fuse feeding power to TCM is good (^^as stated in post above^^)if acts like it is stuck in 3rd gear,sounds like tranny is is limpin mode,which if memory serves me gives you 3rd and reverse, which allows you the ability to drive it off the roadway and most times get it to a service facility ....can be caused by certain codes and or or loss of power to TCM...
Next to the transmission control module there should be a smaller box with a hinged lid inside are relays and fuses to control the neutral safety interlock, cruise control signal, and power for transmission. The internal components are not very robust and can easily be damaged by corrosion and voltage spikes.