ABS light came on, it also knocked out speedometer and odometer and fuel mileage

Your battery. First. The Walmart version is the most affordable. For an emergency. Next step is abs sensor modules. One on each wheel. 80.00 bucks at O'Reilly. Step 2. Just in case check your alternator etc. But, step 3 is your transmission neutral safety sensor. Aka neutral sensor or gear selection sensor. Reason being is that our cars are well known for easily going into limp mode. Or you will get a transmission safety mode in your cluster. It will read transmission -------program. To secure the transmission it will only allow it to run engaged in 4th gear. So as you see. It all stems from low battery! Try bimmerforum.com! Good luck and God bless. Also when the brake pads go low, it will trip out the speed sensors/ and abs sensors. Tripping the ecm/ ecu. Dumping all your gauges and setting off, the limp mode/ transmission fail safe program bs. Your car will take about 2 minutes to pick up speed. Also the weather. Heat can cause battery failure prematurely. And the wet. Can cause conections etc sensors to go bad. So avoid drive through car wash. So wash by hand. Carefully with the water etc. Long trips drive early in the morning or late at night. Until you replace said parts. I am onmy way to vvegas back from California. That dessert pounded on my Lear jet 740il !!! I went into limp mode transmission bla bla bla. Hunted down the culprit. Low battery. In any other car. My battery is good for another 5 years withcare. But in out cars we only have a 2-3% mmargin of error. I believe that I am I. The 1.5% area. I will be getting a full tune up and new battery this week. One clever way to check is also running test 09. Press and hold the information button on your right dash. The mileage one is on its left. You can see it through the steering wheel of your bmw. Once you see test on your info screen, select 9. It should show voltage etc. Do not wait until you can see the battery signal warning! !! Lastly. If you can not read because your pixels are out; just park where you have shade. Put your ac on the lowest setting. If you can see the lights(green that hhighlight your ac functions) fluctuations like a mini sublime light show turn it off and conserve your battery. It's the battery. So no daytime running lights , because they look cool. Operate one window at a time! Same with ac or sun roof. Do not overload a 1-3% battery. Meaning that is 97% good. So start with the battery and then everything else. Battery runs close to $200.00. Good for 3 years. 18-24 months by my standards. Really more like 12-16 months! Every thing else. Replace one or two at a time. Brake pads/ abs sensor/speed sensor. Good for 18 months to just be safe and run perfectly! !! And most importantly. Run your bmw hard. 1-3 times per week. Passing speed. 55-80. For about 20-55 seconds. 2/3 times each day. The car needs it! Remember they are built for 180 mph daily for 20 years. Three times per day! USA is stop and go. Stop and go. Hurts our cars!! Finally. High compression race engines! ! They need lots of fresh synthetic oil. They burn 1-3% of it in the conbustion cycle. So keep your minors like air filters clean and etc. Disclaimer. This is in a perfect world setting. So only apply as needed. Honestly with attention to details. You could easily get over 500k miles from this engine!