Hello my fellow Prostar owners.. unfortunately I am here I have exhausted all leads to fix this issue. Any advise is greatly appreciated. I owned 2015 international Prostar Cummins and with an automatic transmission. I have been fighting issue with electric fault on the dash every time the battery drains or if you let it sit for a week the Tcm would have to be programmed for the last 2 years money pit. Finally mid December when the tech hooks up the computer he was an able to see the Tcm . You can see the ecm and bcm but not tsm. He checked fuses all good. He thinks its the chassis harness, one of his other tech went through it didn't find anything. He suggested we need a new harness. 6 weeks to make it and $5400 for being not sure if its the problem.. any help or ideas. Thanks PS.. 2021 we replaced the TCM with a new one. 2020 we replaced the harness that sits on the top of the transmission
Why are you r batteries draining? When it sits for a week, what is the voltage at the TCM with the key on?
@Heavyd hangs out in the International forum International Forum Usually on the weekends though, he may be able to help. You might read through the International forum to see if there is anything relevant to your problem.
truck is completely off the only thing running is refrigerator even that is turn down. when it sits for week properly between 10V to 12 volt
I would say you have bad main battery positive, ground, ignition or datalink feed to the TCU connector. Next time the TCU is not communicating, remove the OEM connector at the TCU and check the following; Pin 35 - ignition input (key must be on) 12volts Pin 38 - main battery positive 12 volts Pin 36 - main ground Pin 2 - 1939 datalink - 2.4 volts (approx at key on) Pin 3 - 1939 datalink + 2.6 volts (approx at key on) At key off, you should have about 60 ohms of resistance between pin 2 and pin 3 to also confirm if your datalink is good. Main power and ground should also be load tested with a headlight bulb to ensure the wire can support good amperage. If all this is good, your TCM is faulty. Low voltage cranking will take them out.
@Heavyd I believe I have this same problem.. Batteries ran low tried cranking, slow crank then nothing... Message on dash *ELECTRICAL FAULT* ....I replaced the Batteries and same message appears, and still no cranking. How do I get to the TCM.. I have no lift or jacks to get the truck up in the air. Is it accessible through the battery box or from inside the cab.
