"What likely has happened here is the battery has swelled pressing from the bottom onto the Trackpad and the keyboard ribbon cable.
Taking the battery out in this system is a bit tricky! If you've never worked on a MacBook I would let either Apple or an Apple authorized service center repair your system. To give you an idea whats involved review this: MacBook Pro 13"" Retina Display Mid 2014 Battery Replacement
Update (05/21/2017)
@iefes - Yves The diagnostic codes are clear here you have a hardware level issue! Sorry there is no magic software fix here. You can see for your self in the link I provided below. You stated you didn't spill any liquids into your system. Did you spray any kind of cleaner onto the keyboard or trackpad? You could have inadvertently damaged things here.
NDK001, NDK003 & NDK004 There may be an issue with the keyboard.NDR001, NDR003 & NDR004 There may be an issue with the trackpad.
Contact Apple or take your computer to an Apple Authorized Service Provider or Apple Retail Store to determine which service and support options are available."
I had this exact same issue. Basically just replace the entire trackpad assembly! Not the ribbon. Posted here about it! (MacBook Pro 13 (Mid 2014) - Erratic Keyboard and Trackpad)
I had the same issue but i managed to fix it. For me the problem was not in the cable but in the trackpad itself. I’ve read that there is a certain chip on that trackpad that controls the trackpad and keyboard. So to fix the problem just replace the whole trackpad and it should work like normal. (My battery was not swollen)
"Sorry for reviving an old thread, but I’m having the same problem with my 2014 13.3” 2014 i5. I did spill liquids in the trackpad, but I don’t think any got into the keyboard (all keys seems to work fine), but I can’t say for sure. Fan is running at full speed and the performance is quite poor. I disconnected the keyboard, keyboard backlight and trackpad ribbon cables, without any change to neither the fan speed nor the performance. I would believe if the trackpad and/or keyboard was faulty, disconnecting it would temporary correct the issues? I also disconnected everything to eliminate other hardware (IO board, speakers, webcam, etc, all connectors). I ran it on only the charger (with mag-safe board connected and battery disconnected), then disconnected the mag-safe board and ran it from battery only. No change. I tried both SMC and PRAM reset, fresh installed Catalina. Nothing helps.
Any tips? I’ve also inspected the logic board under the microscope and can’t see any damage. Could the liquid damage to the trackpad fry something on the logic board? And where do I start to trace the error?"
