SPN 521

[Waterloo]

On my 2008 ProStar I had the TC, ABS, Engine brake and Red triangle of death lighting up every once in awhile on my dash. I wound up at the dealer, they told me it was my “compass”... I said, “What compass”

He said, “This compass, right here in the odometer screen.”

Then he asks, “Where is your compass?”

Me, “Hell, I didn’t know I had one!”

Long story short, all of the above items in my list of idiot lights that lit up, are wired through the N, S, E, W compass module. He used DLB to discover that. So in other words, it could be any number of sensors or modules in the truck. I never would have figured any of this out on my own. Sometimes the dealer is it.