E53 3.0d facelift with M57N engine has two versions. EU3 without DPF has vacuum actuated turbo, EU4 with DPF has electric servo actuated turbo. (Otherwise the same GT2260V.) (Same thing was on early E6x 530d.)

That trouble code for smooth running controller means that correctional value on some injector has been over the accepted tolerance. Though those present values are still within specs. This code has no direct correlation to any possible power problems.

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E39 530dA -02 M-Sport Messing metallic
E53 X5 3.0dA -06 Sport Stratus grey
E70 X5 40d -12 M-Sport Space grey