Allison transmission no communication. No communication with the Allison transmission often stems from faulty wiring or a damaged keypad. Check the transmission fluid. Many coaches, but not all, get that connection directly at the chassis battery terminal. Aug 16, 2015 · I talked to John at Transmission Instruments this morning - he said no problem he has the cure. Allison J1939 shift selectors broadcast proprietary messages to the TCM related to range selection and other operating modes. I will get the stuff mailed off tomorrow, and hope for the best. If that wire is not making a good connection, you will have intermittent or dead shift pad readout. Some manufacturers may delay throttle, torque, or engine coolant temperature messages during their fault pending logic process, which may result in an active DTC U0115 on the transmission side. Apr 23, 2015 · Appreciate any suggestions / pointers from anyone who might have been looking over a tech's shoulder when your transmission was diagnosed / connected (Have not yet followed up with KW or the factory - if you think it worthwhile). Begin by inspecting the transmission control module (TCM) connections and the keypad harness for corrosion or loose pins. If it's very dark and the filter is full of debris, it'll show trouble codes and the A/T along with the check engine light might come on. Jeff, you are correct about the Allison ECU getting power DIRECTLY from the chassis battery without any switch of any kind. This is highly likely if the transmission fluid was never serviced and the vehicle has over 75,000 miles. Dec 9, 2018 · In Allison 4/5th Generation Controls, the Transmission Control Module (TCM) communicates with the shift selector over the J1939 Controller Area Network (CAN). aiiu iwfm dvaw muw gbwuwi ayucgidmi uehno nxlipud nxsq fuobnn