What does the little wrench light mean?

That means the scheduled maintenance is due. Different type of services needs to be performed based on the mileage. Zee

There is one or two wrenches displayed within the instrument cluster indicating “A” or “B” service with the Flexible Service System maintenance system there is a minor or major service designated as “A” or “B” respectively. If the last service performed was an A-service, than the next service will be a B-service.