BMW fault code 004B

Trailer module

Actuator travel sensor 2 positive reference voltage < minimum

Module version: Trailer module (AHK)

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 004B is a BMW code, stored in the car's trailer module, 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 trailer module is on: 8 Series (E31)

← 004A All trailer module fault codes 004F →