Originally Posted by wstar

I highly recommend getting an OBD-II tool. Not having one when working with modern cars is like not owning a screwdriver these days, and they're universal so you can use them to help out friends and stuff too. Then instead of pulling the battery cable and hoping the condition goes away (and never knowing what it was referring to), you can get an exact readout from the ECU. This Actron is the one I have. There are many mfgs to choose from and they're all pretty equivalent. I mostly picked this one because it gives a text message describing the codes, so you don't have to look them up online or on some chart.