BMW X5: Rear Axle

 Emissions Management

The N54 and N52KP meet ULEV II requirements for 2007. There are not many changes to the emission systems on these engines. The N54 engine has 2 underbody catalysts in addition to the "near engine" catalysts already in use from the N52. The N51 engine, however, is a SULEV II compliant engine which

 Limp-Home Mode

If a fault is diagnosed in the system, such as e.g. failure of the high-pressure sensor, the fuel-supply control valve is de-energized; the fuel then flows via a so-called bypass into the rail. In the event of HPI limp-home mode, turbocharging is deactivated by an opening of the wastegate valves.