BMW X5: 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.
Causes of HPI limp-home mode can be:
- Implausible high-pressure sensor values
- Failure of the fuel-supply control valve
- Leakage in the high-pressure system
- Failure of the high-pressure pump
- Failure of the high-pressure sensor
![Engine Service Information](images/books/1905/index272(4).png)
Fig. 56: Identifying Limp-Home Mode Diagram
Fuel System Safety
Working on this fuel system is only permitted after the engine has cooled
down. The coolant temperature must
not exceed 40ºC. This must be observed without fail because otherwise there is a
danger of fuel sprayback on
account of the residual pressure in the high-pressure system.
When working on the high-pressure fuel system, take particular care to ensure
conditions of absolute cleanliness
and follow the work sequences described in the repair instructions. Even the
tiniest contaminant's and damage
to the screw connections on the high-pressure lines can cause leaks.
![Engine Service Information](images/books/1905/index273(4).png)
Fig. 57: Identifying Fuel System Safety Label
![Engine Service Information](images/books/1905/index274(4).png)
Fig. 58: Identifying High-Pressure Fuel Lines
READ NEXT:
It is the outward-opening piezo-injector that renders possible spray-directed
direct injection and thus the overall
innovations of the N54 engine. Due to the fact that only this component ensures
th
The movement of the nozzle needle in the injector is generated no longer by a
solenoid coil but rather by a
piezo-element.
A piezo-element is an electromechanical converter, i.e. it consists of a ce
Most of the ignition system components have remained the same for all NG6
engines for 2007. There are some
minor changes to the ignition coils that apply to all versions. The coils have
been optimiz
SEE MORE:
Special tools required:
52 0 050.
Necessary preliminary tasks:
Remove rear seat.
Remove rear panel trim.
Disengage welt in marked area from seat mechanism.
Disengage welt in marked area from seat mechanism.
Installation:
Make sure metal lugs in welt are correctly engaged.
Version with seat
Necessary preliminary tasks:
Remove fresh-air grille in rear cabin.
Remove trim from rear cabin monitor base at front.
Release screws (1) and remove rear cabin monitor with holder (2).
Disconnect associated plug connections and feed out leads.
Tightening torque.
Fig. 39: Identifying Rear Ca