P0733 code AT light on no 4th gear
Hello. I just joined the forum today and posted the same question about my M3 sport. The engine revs in 4th and the AT light comes on immediately. From all my research, the ecm is the 2 main wiring harnesses attached to the battery box. Also, there are speed sensors attached to the transmission casing. The input turbine sensor and the vehicle speed sensor VSS. These may have an affect on shifting, along with shift solenoids. I replaced all my solenoids on my car,, replaced the VSS and cleaned the input turbine sensor. Still same problem. See pictures of speed sensors attached. I'm waiting for a response and hope my information helps you in any way.