BMW fault code 0091
Engine electronics
In the engine electronics, code 0091 means different things depending on the version of the module in the car. Find your car below; the app shows the right one for yours.
Misfire cylinder 1
Module version: Motor Electronics (BMS46DS0)
In: 3 Series (E36) 1990–2000, 3 Series (E46) 1998–2006
DME: Misfire relevant to exhaust gas, cylinder 1 (EUIII code: P0301)
Module version: Motor Electronics (BMS46DS1)
In: 3 Series (E36) 1990–2000, 3 Series (E46) 1998–2006
Lambda controller 2
Module version: Motor Electronics (BMSS501)
In: 3 Series (E36) 1990–2000
DME: Fuel system minor leak detected; fuel cap possibly not secured (OBDII: P0442)
Module version: Motor Electronics (MS420DS0)
In: 3 Series (E36) 1990–2000, 3 Series (E46) 1998–2006, 5 Series (E39) 1998–2003, 7 Series (E38) 1998–2001
DME: Function, oxygen-senosr control, cyl. 4-6
Module version: Motor Electronics (MSS54DS0)
In: 3 Series (E46) 1998–2006
Reading and clearing it
Fault code 0091 is a BMW code, stored in the car's engine electronics, not a generic OBD2 code (P0xxx): a generic OBD2 reader only reaches the engine's emissions faults, so it won't show it. AutoLingo for BMW reads it with BMW's own diagnostic protocols, in plain English, with the details the module stored about it, and clears it after a repair. If a fault comes right back after it's cleared, the problem is still there.
The engine electronics is on: 8 Series (E31), 5 Series (E34), 3 Series (E36), Z3 (E36/7), 7 Series (E38), 5 Series (E39), 3 Series (E46), Z8 (E52), X5 (E53), X3 (E83), Z4 (E85), Z4 (E86)
Coming soon
Enter your email address to hear when AutoLingo for BMW is ready.