We have a 2009 freightliner cascadia with a DD15 that won't crank. If you jump it at the starter it will not start but only turn over, even with key on. It is throwing code SPN 677 FMI 5, open circuit in starter relay. We have replaced the starter relay, and the wire that the code recommends checking from pin 21 at the ecm to the relay. We overlayed a whole new wire and still the same problem. It has us all stumped. Any help would be appreciated. Thank you
Do you have the last 6 of the VIN? I thought the older Cascadias used the Sam Cab for the output driver for the starter. I could be mistaken though.
