P12A8

121202 - P12A8

Information saved in
DME

Fault code
121202 - P12A8

Fault text
Charge-air pressure sensor, run-on: pressure too low

Fault description
During the control module's shutdown phase the diagnostic
function monitors the barometric pressure sensor, intake-
manifold sensor and the pressure sensor on the air-intake
side of the throttle valve to determine whether they are all
measuring the same pressure.

Condition for fault identification
Test condition:
The fault is recognized when the display for the sensor value
on Bank 1 deviates by 330 mbar or -10 % during the
shutdown phase.
Potential problem source(s):
- Defect in wiring harness
- Charge-air pressure sensor defective
Terminal condition: none
Voltage condition:
- Electrical system voltage > 10 V
Temperature condition:
- Intake air > -10
- Control module temperature > -10
Time condition:
- 5 seconds after engine stops during post-operational
shutdown phase
Other conditions:
- none

Condition for fault memory entry
This fault is logged in the control module's fault memory if
it remains present for longer than 2.2 sec.

Action in service
- Check wiring harness
- Replace boost-pressure sensor

Fault effect and breakdown warning
Breakdown notice:
- none
Possible apparent symptoms:
- none

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

Service instruction
- none