Hi 👋 all 

Having trouble the last few weeks with an intermittent fault code 00814 Brake Pressure magnetic coil,  recently changed the brake fluid and full brakes pads & discs ( dot 4) all fine until after 6-7 weeks whilst leaving the supermarket the brakes started locking on , the ABS & ESP light came on as well as "RHL speed sensor fault" so when I got home I ordered the speed sensor as it wasn't recognised on the OBDELEVEN,  anyway I've changed this after 3 days and used the car locally In between and another fault ( 00814) has been logged ?? The ABS & new speed sensor are fine and codes cleared,  I've heard horror stories regarding the brake servo being replaced however its not always solved the problem ?? Its not the bearing and reluctor ring inside as it records the vehicle speed on each wheel , I'm wondering if the brake fluid which was to the top of the cap 🤔 was overfilled at the garage on service and possibly caused damage , however the brake pressure sensor is working as it records 0.64 bar when normal then over 140.00 bar when I depressed the brake pedal ! Any help 🙏??? Please 

2 hours ago, LEE M HOPPO said:

Hi 👋 all 

Having trouble the last few weeks with an intermittent fault code 00814 Brake Pressure magnetic coil,  recently changed the brake fluid and full brakes pads & discs ( dot 4) all fine until after 6-7 weeks whilst leaving the supermarket the brakes started locking on , the ABS & ESP light came on as well as "RHL speed sensor fault" so when I got home I ordered the speed sensor as it wasn't recognised on the OBDELEVEN,  anyway I've changed this after 3 days and used the car locally In between and another fault ( 00814) has been logged ?? The ABS & new speed sensor are fine and codes cleared,  I've heard horror stories regarding the brake servo being replaced however its not always solved the problem ?? Its not the bearing and reluctor ring inside as it records the vehicle speed on each wheel , I'm wondering if the brake fluid which was to the top of the cap 🤔 was overfilled at the garage on service and possibly caused damage , however the brake pressure sensor is working as it records 0.64 bar when normal then over 140.00 bar when I depressed the brake pedal ! Any help 🙏??? Please 

Hi which brand of brake fluid was used when it was changed I have found that you can't just use any DOT4 as this caused quite a few component failures on my car until I settled on Comma ESP4 this is as close as you get to OE without the price tag, even the garage I use has started using what they call the expensive stuff as 2ltres is about the same as what they would have paid for a gallon of the trade stuff, all brake fluid is hydroscopic, [absorbs water] but having done some research it seems the cheaper fluids absorb water faster and the majority of modern car breaking systems rely on fluid viscosity, worth a try?. PS you can't cause damage over filling a brake reservoir.

Steve.

Yeah I tried with new comma 4 brake fluid and still the same 🤔, i get a slight fluctuation/ flicker on the brake pressure reading from 0.64 to 0.88 when normal however I get a full 120+ when I Press the brake pedal , going to check the wiring around the brakes see if there's a split 

Looks the ABS is a fault , the 00814 is the brake servo but it's working as the pressure sensor inside is recognised,  the ABS pump is working when I engage it on the OBDELEVEN so I'm hoping it's software issue as I've changed the faulty speed sensor or it's a electrical issue with thr ABS . 

Hello @LEE M HOPPO did you ever resolve this issue? I'm experiencing similar. I have replaced the battery and also used OBD11 to get the ABS pump to cycle and it seems to be operating well. Not sure what to test next or where to troubleshoot.