1HTWMAZN1BJ381943 Maxxforce 10 Allison 3000 I hope someone has come across this before or at least has some insight for me... So this is a new to us truck. Was told it was parked about a year ago, ran fine, no issues. When we came to pick it up they claimed the transmission was in "safe" mode and wont start. Got it back to the shop. New batteries. Cleaned connections. No crank. No codes. Everything is communicating. Shift Panel has a dash and a zero with an asterisk in the center. Not a cat eye. Again, no codes. Checked all fuses. Called Clarke, gave symptoms and they said it needs a TCM. Installed new TCM. No change. Clarke comes out to inspect. Tests CAN wires, powers, grounds, No issues. Claims the shift panel must be bad. New shift panel. The truck now cranks but weirdly slow and no start AND NOW it has Cat eyes, communication error codes between the TCM, BCM, And ECM. Visually check all harness' and connections. Nothing. Plugged the old shift panel back in. All goes back to "normal" but no crank. Clarke says the shift panel is bad. Put in ANOTHER shift panel. Same. I dont wanna haul it off to the dealer, Im sure it must be something "easy" Clarke just wants to throw parts at it.
It sounds like a data link issue to me. The wiring harness that goes to the transmission and TCM is prone to rubbing where it runs across the top of the transmission. With the key on check the voltages of the two data link wires to ground. should be close to 2.5 volts with one slightly higher than the other. With the key off measure between the data link wires and ground using the ohms scale. reading should be infinite.
Ill verify myself, Clarke claims to have checked all that and it checked out fine. Although it still makes no sense that it communicates fine with the old shift panel but not the new.
I have found that the Maxxforce engines are nothing but constant trouble. Most people who have them, take them to a dealer, get them running good, and sell them quickly. Sorry you are having trouble with it, but not surprised at all. IF, you can get it running, get rid of it ASAP. You will be glad you did.
The shift panel or WTEC or World Transmission Electronic Control. If you push the up down arrows at the same time it will scroll through several different functions. When you get to fault codes you can scroll through the codes using the up or down arrow. You should be able to look up the codes on the internet. I see Allison has locked down all access to their manuals.
This should cover your WTEC: https://www.rvtechlibrary.com/transmissions/3000_4000_operators.pdf
Its doesn't have any codes, thats the thing. I have Allison software. The only time i get codes is with the new shift panel and they are communication error codes for the TCM, BCM, And ECM
Its a data link problem!
How?? If i can communicate with all systems with no codes when the old shift panel is in then that automatically tells me there is NOT a can issue.
What are you using to scan it? Can the software see the TCM and BCM?
Yes. I have Allison, Nets, and servicemaxx. As i said in the initial post. Powers, grounds, as well as CANs have been checked and tested. When the old shift panel is installed everything is communicating, no codes, but i have no crank. New panel. I have codes pertaining to communication errors, slow crank. No start.
The part number for the shift panel that came installed in your truck is: 3686142C1 What is the part number of the one that Clarke installed?
Hadn't updated in a bit. Went back through everything clarke did and retested my powers and grounds. Verified everything was clean and tight and viola! Everything works and the truck is running. They must have left a connection somewhere loose and me going back through it resolved the connection issue.