P306B

11AA02 - P306B

Information saved in
DME

Fault code
11AA02 - P306B

Fault text
Fuel supply system: Pressure too high, emergency operation
with injection deactivation

Fault description
The diagnostic function monitors fuel high-pressure system
to detect whether it rises above a defined maximum value.

Condition for fault identification
Test condition:
The fault is recognized when the rail pressure rises above 25
bar.
Potential problem source(s):
- Defect in wiring harness between DME and rail-pressure
sensor
- Defective rail-pressure sensor
- Defect in low-pressure system
- High-pressure pump defective
Terminal condition: none
Voltage condition:
- Onboard electrical system voltage between 9 V and 16 V
Temperature condition:
- None
Time condition:
- None
Other conditions:
- none

Condition for fault memory entry
The diagnostic fault code is logged when the fault remains
present for longer than 1 min.

Action in service
- Check wiring harness between rail-pressure sensor and
DME
- Replace rail-pressure sensor
- Check operation of fuel pump
- Replace high-pressure pump

Fault effect and breakdown warning
Breakdown notice:
The engine reverts to its limp-home program, continued
vehicle operation is possible but drivability is restricted,
because power is reduced the driver should refrain from
passing maneuvers.
Possible apparent symptoms:
- Loss of power

Driver information
Warning light:
- ECE emissions warning lamp: on
- ECE electronic engine power reduction: on
- CC message: on
- US emissions warning lamp: on
- US electronic engine power reduction: on
- CC message: on

Service instruction
None