2023 BMW M340i Service and Repair Manual

This factory service and repair manual for the 2023 BMW M340i has one drivetrain to explain and explains it in detail: the turbocharged 3.0L DOHC inline-six running as a gasoline mild hybrid, in a four-door sedan with Base as its only specification. Mild-hybrid assistance changes how the engine starts, charges and idles, so the electrical machine is treated as part of the powertrain, with its own procedures alongside the engine mechanical, fuel, ignition and cooling material.

Engines covered

• 3.0L inline-six mild hybrid — DOHC, turbocharged, gasoline

Body styles covered

• 4-door sedan

Trims covered

• Base

Known issues on the 2023 M340i. Coverage is deepest where a technician needs it most. The inline-six's mechanical section gives disassembly and reassembly sequences with the clearances and torque values each stage is checked against. Cooling and lubrication procedures include filling, bleeding and pressure testing. Charge-air and boost control material explains what to inspect when the engine underperforms, and fuel and ignition testing follows the same pattern. Wiring diagrams cover the sedan circuit by circuit, and the diagnostic chapters set out how faults are read from the control units and verified.