So a week ago I was getting on the highway ramp and drove into a little bed of water about an inch tall. My car automatically went into neutral when I entered the highway. I immediately turned the car off and was not able to get the car to turn back on. The car kept saying “Start Engine to select Park or Neutral” I sat in the bed of water for about an hour and a half before a tow arrived. The car still will not start and keeps saying BATTERY 12 V. I tried to get the car jumped multiple times and it still don’t start. the water did not enter the vehicle whatsoever! Mercedes is asking for $1100 to do a diagnostic to pull the carpets up and check the wires .. ANY ADVICE or should I just pay for the diagnostic??? Should I take it somewhere else? Maybe it just needs a new battery

Get a second opinion. But you need to scan for codes with a Mercedes-specific scanner. This may also help. But if what you say is true and you only went through a puddle, you should not have water damage.

Definitely get a second opinion. Your ‘21 CLA should have basically the same engine, transmission, electrical system as my ‘21 GLB. It’s an SUV, so a bit higher, but it’s our utility vehicle and slogs through mud, water, and does mild off road with no issues at all. Unless you pulled water into the air intake and it got past the filter and air box, I don’t see a reason to start off with an $1100 flooded car diagnosis. A ‘21 should still be under the original warranty unless it’s over 50k miles. I think they should have started there and worked forward after initial diagnosis.

Good points, Piggy.

@Nikki_ Does the car turn over, at all? Does it sound normal when you try to start it? Are the underside splash trays in place?

Get a scanner specifically for Mercedes and scan for codes.

that's key, your car lost communication with the gearbox, check the underbody connectors, maybe your car will start again for little money