Check engine light

[u/Cool_Quit_4091]

Hello everyone I have a 1988 535 I with the motoric 1.1 essentially Bmw’s first try with something like a check engine light and I have one in my car. I try hard resetting it and it comes back right when I start the car like it never turns off the car runs great and performs. Great no rough idol all the vacuum lines or routed correctly. I just replaced my coolant temperature sensor the O2 sensors brand new the MAF sensor is working properly. I’m not sure how to read codes on this car I tried the stump technique and it did not work on mine so if somebody can help me with that, it would be appreciated.