BMW fault code 520D

Transmission control

SMG: Signal, idle speed, is faulty (DME)

Module version: Transmission control unit (SMG_60)

Which BMWs have this version depends on the engine and equipment, so we don't list them here; AutoLingo for BMW reads which version your car has.

Reading and clearing it

Fault code 520D is a BMW code, stored in the car's transmission control, 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 transmission control is on: X5 (E53), 5 Series (E60), 5 Series (E61), 6 Series (E63), 6 Series (E64), 7 Series (E65), 7 Series (E66), 7 Series (E67), X5 (E70), X6 (E71), X6 (E72), 1 Series (E81), 1 Series (E82), X3 (E83), X1 (E84), Z4 (E85), Z4 (E86), 1 Series (E87), 1 Series (E88), Z4 (E89), 3 Series (E90), 3 Series (E91), 3 Series (E92), 3 Series (E93)

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