When your 2022 BMW X3 displays the P0305 code, the diagnostic approach depends on your engine. The G01 2022 X3 offers four-cylinder and inline-six options. P0305 is valid on M40i's inline-six but anomalous on xDrive30i's four-cylinder.
2022 X3 Engine Options
The 2022 X3 offers the 2.0L B48 turbo I-4 (248 hp) and 3.0L B58 turbo I-6 (382 hp in M40i). Only the inline-six has cylinder 5.
Diagnosis
On the B58, cylinder 5 is toward the rear. Common causes include spark plug wear, ignition coil failure, and carbon buildup on direct-injection engines.
Four-Cylinder
xDrive30i has only cylinders 1-4. P0305 is anomalous.