ML430 stuck in park what to do?

There is a small window near the bottom of the shift pattern on the shifter. Get a dowel about 1/4" (6mm) in diameter or the back of a cheap BIC pen and press it through the small window straight down. You should feel a springy resistance of a mechanism. This is the locking override for the shifter. Be certain that you have the brakes depressed when this is carried out! Once you find the springy lever with your tool of choice then shift out of park. Remember the vehicle will start in park or neutral only. Never park the vehicle in neutral! All that said. The root cause is likely the brake switch.

REPLACE THE MAIN BATTERY!!! The diagnostic computer test may not read it or be specific, but try replacing the main battery first. Unfortunately for me, we tried replacing other parts and after $1000, it ended up being the battery!!!

If you are only doing short runs, over a period your battery will become depleted and, not always but sometimes you will find your ML locked in park. Give your battery a jolly good charge and then start the car, press firmly down on the brake pedal (firmer than normal) and 9 times out of ten it will be fine. You will be able to get the car out of park and things will return to normal. A regular battery charge is no bad thing.