Mina Azez

I got a new Autel scanner today and wanted to see what it would say about my beloved clk550. Under the esp section it says terminal 30 under voltage. Im thinking it is the reason why my brake pedal is hard. Ive replaced the front pads and rotors with hardware, rear calipers, pads and rotors, and flushed/bled the brake fluid multiple times. The only time the pedal felt right was when I was replacing the rear suspension and had to remove the rear caliper and when I reinstalled it the brake pedal felt proper but after a couple miles it was went back to abnormal. After this I decided to replace the rear calipers but made no difference. I'm thinking it could possibly be the brake pressure sensor. Any suggestions on what parts I should throw at it first?

Plutoe

Follow the instructions of the scanner---what esp fault bla bla!

Rudeney

Undervoltage errors are quite common if you've ever had a bad battery. It even happens sometimes on very hot or cold days where the battery is taxed. I seriously doubt that this is in any way related to your pedal feel since that is all hydraulic. Maybe you have a problem with the vacuum operated brake booster?