B50D04 Mercedes Fault Code :
Read the description of B50D04 in ACM02T and the engine lights up for ACM02T - Exhaust aftertreatment (17A03) code, there are some possible causes for it.
The output for the power supply of components '17B11 (Exhaust back pressure sensor upstream of diesel particulate filter (DPF))' and '17B12 (Exhaust back pressure sensor downstream of diesel particulate filter (DPF))' has a short circuit to ground.