The adjustment motor for the transfer case on some BMW models, X3 (E83), X5 (E53, E70), X6 (E71, E72), can cause acceleration problems and trigger trouble code warnings.

Problem
A clicking noise can be heard from underneath the vehicle - around the area of the transfer case - when switching the ignition on or off.
The engine is jerky in operation when accelerating in lower gears.
The ABS, 4x4 and brake system warning lamps are illuminated - related to the symptoms listed above. These possible fault codes may be stored in the transfer case control unit:
    • 539E Control motor or transfer case faulty.
    • 5463 Transfer case mechanical fault.

Cause
Wear of the transfer case adjustment motor drive gear - often caused by an excessive variance of tyre tread depths between the front and the rear axle.

Solution
To check that all systems are fully functional, carry out a full system scan of all fault codes using a suitable diagnostic tool.
Check the transfer case adjustment motor operation and replace as necessary, then clear/reset all fault codes after the repair.
Check the tread depths of all the tyres and replace as necessary.

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