My light comes on every morning then goes out after I get down the highway a bit and the engine warms up. This morning at 5:30 am it even had the shut down light on. It never did but scared me. Then they went out for the rest of the day. My battery terminals look clean, I did notice a wire on the alternator is a little rusty? Any Idea's? Oh yeah its a 02 Mack.

turn off the cruise with engine on.  hold the accel\resume botton 3 sec.  lookin at the EML light, it will start flashing.  count the flashs, there will be a pause, count the flashs.  more then likely its 2 - 9.  phone up mac and give them the code to tell you what it means.  if that dont work, ?

NEEDS ANTIFREEZE!

Interesting.. Thanks, I will.

Anti Freeze? Huh, could be. I had to add some to the out side reserver, last month. Will check,thanks.

yea check and let me know. we had one that did the same and it needed antifreeze in the resivor

I agree!  Check engine coolant.  There are sensors that will cause your dash warning lights to come on, and, if it is low enough it will turn the "shutdown" lights on and turn off your engine. I found that coolant will begin to leak from around hose clamps that are not quite tight enough in the fall when the temperature changes.  Coolant will only drip out when the engine is cold overnight.  After warm-up, it won't leak at all! Something about thermal expansion.........hope this helps.

Yep, antifreeze is the first culprit. 

Bad ground on other sensors second.

3) Bad sensors. 

As an aside, if you get random shut downs, or no response to throttle inputs, then replace the electric foot pedal, an easy DIY, and the Mack stealership likely won't figure it out on their own, given their own troubleshooting procedures.

I had to add 1.5 gals. of ani freeze. The light still came on this morning but went off soon after a short drive. It came on again while pumping for a little while, but then not for the rest of the day. I'll check again tomorrow. I think it was the problem but the fluid just hasn't all got in the radiator from the reservor? What kind of fool designed a low coolant light as ELECTRONIC MALFUNCTION?

The light went on again today, not the shut done though. i think I had a double trouble and the antifreeze cured the major one. I'll have to do the diagnoses light test next time it goes on. I'm usually on a pump run though and don't have time. Will see. Thanks

Might have to pull the sensor and inspect. Some times they get a layer of crap around the sensor arms. wipe them down and re install. Had that happen to one of our machines.

You have a bad electronic fuel injector or a eup very commen check it out scan the truck!!!