New to the form any help is appreciated. I have an 02 RD 688 with the 460. When i bought the truck it had the problem and i have chased it since. You will be going along and the tack will go to zero for a few seconds engine dies and then restarts. The local mack garage changed both speed sensors and over the winter i sent the ECM out thinking it that it might be that. I drove the truck yesterday and it still has the cut out.
Other issues
When you go to shut the truck off sometimes you have to turn the key back and forth a couple times before it shuts down. I have checked the wiring and replaced the key switch hoping to fix the issue with no success. Not sure if the 2 are related or not but any thoughts on this issue is appreciated.
When you plug into the truck it had/has a code for the pyrometer. But there isn't an engine light on the dash. Mack said the bulb was missing but i pulled the dash and its a sealed unit