Manufacturer Code Charts: 120308

120308 - P0299

Information saved in
DME

Fault code
120308 - P0299

Fault text
Charge-air pressure control, lower value: charge-air pressure
too low

Fault description
The diagnostic function monitors the pressure measured by
the boost-pressure sensor.

Condition for fault identification
Test condition:
The fault is recognized when the monitored pressure is less
than the specified pressure.
Potential problem source(s):
- Boost-pressure sensor defective
- Defective electropneumatic pressure converter in
wastegate valve
- Wastegate valve is defective (seized in open position)
- Air-induction tract between turbocharger and intake-air
plenum has leak
- Vacuum line for controlling wastegate valve is defective
Terminal condition: none
Voltage condition:
- Onboard electrical system voltage between 9 V and 16 V
Temperature condition:
- None
Time condition:
- None
Other conditions:
- Engine speed above 1900 rpm
- Engine load
- Turbocharger boost in control range

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
- Boost-pressure sensor
- Check electropneumatic pressure converter
- Check vacuum line and vacuum
- Check air-induction tract between turbocharger and intake-
air plenum for vacuum leaks

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:
- Reduced power

Driver information
Warning light:
- ECE emissions warning lamp: off
- ECE electronic engine power reduction: off
- CC message: none
- US emissions warning lamp: on
- US electronic engine power reduction: on
- CC message: on

Service instruction
None