I am experiencing the battery warning light, the oil light, the radiator light and the bake light coming on the instrument panel of my 1992 L S400; I have a brand new battery, the oil is full, the radiator is full and the engine is not overheating, etc

Lexus just did a full 200,000 maintenance (tune up, oil change, coolant flush, lube, gaskets, everything) 2 months ago and everything was found to be okay.

It seems to come on SOMETIME when I'm going slow (under 30mph) or stopped but when I speed up, it goes off.

It drives fine too - I took it on the highway to 65mph.