XSeries-forum

Hi All,

I have developed a problem with my X3.
A few weeks ago while driving at around 55-60mph I went to overtake and the car just felt flat and failed to accelerate. I presumed the MAP sensor and running Carly seemed to agree.
I first tried cleaning with electrical contact cleaner and it seemed better so bought a new one last week. A couple of days later it happened again so checked vac pipes which all seemed ok (I did replace them with silicon a couple of years ago). Again diverter valves were changed for the newer model early last year for preventative maintenance.

Tonight it happened again and this is the freeze frame from Carly for the error:

*** 3F01:Boost pressure sensor signal ***
Fault-Set 1 - ( 101984 km)

    Air mass per cylinder: 283.57 mg/Hub
    ambient pressure: 994.46 mbar
    battery voltage: 14.01 V
    Boost pressure actual value: 364.31 mbar
    Coolant temperature: 92.29 deg C
    Engine speed: 1489.45 1/min
    Injection quantity: 7.88 mg/Hub
    Rail Pressure Is: 346.58 bar
    vehicle speed: 50.34 km/h
    Voltage boost pressure sensor: 21.65 mV

Fault-Set 2 - ( 101984 km)

    Air mass per cylinder: 460.01 mg/Hub
    ambient pressure: 994.46 mbar
    battery voltage: 14.01 V
    Boost pressure actual value: 393.85 mbar
    Coolant temperature: 89.28 deg C
    Engine speed: 1323.96 1/min
    Injection quantity: 18.12 mg/Hub
    Rail Pressure Is: 425.35 bar
    vehicle speed: 32.57 km/h
    Voltage boost pressure sensor: 21.65 mV

Any ideas?

Cheers

You've answered your own question....new MAP sensor required or you have a vacuum leak

Mine had a similar issue and I replaced Air flow meter . Can’t remember fault codes off hand though.