So when I start up my car the first couple of seconds the dash displays the 2 wrenches and the number 600. After driving more today now it has the two wrenches and the number 500. What does this mean? I just had the crankshaft position sensor replaced so didn't think it could be part of that.. Any ideas?

I tried searching but everything came up taking me to random links. Any help is greatly appreciated. Heading out of town and need to get it fixed if it is very important.

Thanks!