When your 2024 BMW X3 displays the P0305 code, the diagnostic significance depends on which engine is installed. The 2024 X3 offers four-cylinder and inline-six options. P0305 is valid on the M40i's inline-six but anomalous on four-cylinder xDrive30i models.
2024 X3 Engine Options
The 2024 X3 offers the 2.0L B48 turbo I-4 (248 hp in xDrive30i) and 3.0L B58 turbo I-6 (382 hp in M40i). Only the inline-six has cylinder 5.
Inline-Six Diagnosis
On the B58, cylinder 5 is toward the rear. As a newer model, check for TSBs and manufacturing issues. Standard misfire causes include spark plug and ignition coil problems.
Four-Cylinder Models
xDrive30i has a 2.0L four-cylinder where P0305 is anomalous. Investigate diagnostic system errors.