shawnparks

Can't win this one. Put a new ECM on the truck and the 4 DTC codes that were showing went away and the engine hour meter is back to reading correctly, but the truck still won't crank. It now has a code on the VECU saying that there is a grounded or broken wire. Anybody have any suggestions??

Brother, you hit the nail on the head!! Just checked the hour meter and nothing but dashes. All of the fuses in that lower left box check good for continuity. I have been suspicious of the ecm going haywire for a couple of years now, but everyone says not likely. I had a brief spell on a trip a couple of years ago that the truck acted strange on the interstate and the lightning bolt and other lights came on. By the time I got off the interstate and checked under the hood, the lights were out when I got back in the truck. The truck has never had the same power since that incident and occasionally still flashes those warning lights briefly, but never stay on long enough to get it checked. The best that I can remember, the hour meter was showing around 5 or 6 thousand hours prior to the original incident. Ever since then, the hour meter jumped to 9,999 and has stayed there ever since. THANK YOU for your help!!

I have an 09 Mack with an MP-8 also. Has anyone ever gotten the message 'operation failed' when checking for diagnostic codes? Whenever I have checked for DTC codes in the past, if any were present, they have always came up with the proper code numbers. I left the truck idling to load a machine on the trailer and got ready to leave and noticed the truck had shut down. All of the electronics and A/C were still on but the engine had shut down and no alarms. This truck does not do that like the newer ones do. Turned the ignition switch off and back on to fire the truck back up, but the starter will not turn over. The relay under the CB is clicking, the batteries have proper voltage and proper voltage at the starter but will not engage. After this happened, I checked the DTC's and when I go to the 128 Engine code section the 'operation failed' keeps coming up. The ABS, Cluster and VECU all come up with codes which all show up to be a J1939 data link connector. The dealer says that this is the entire wiring harness. My suspicion is the ECU has gone haywire since the engine code shows 'operation failed'. Has anyone had this pop up on their codes?