P2251

2AAB - P2251

Information saved in
DME

Fault code
2AAB - P2251

Fault text
Oxygen sensor before catalytic converter, virtual earth

Fault description
Pre-catalyst oxygen sensor, virtual ground

Condition for fault identification
Test condition:
Engine running
Terminal condition: Terminal 15
Voltage condition:
1.47 V < Voltage of bank 1 pre-catalyst oxygen sensor with
offset correction ua10mo_w < 1.53 V

Condition for fault memory entry
5 sec.

Action in service
Check wiring harness between DME and oxygen sensor in
front of catalyst; M_LSV1
Replace oxygen sensor in front of catalyst

Fault effect and breakdown warning
It is possible to continue driving. Because the oxygen sensor
cannot be used for closed-loop control the exhaust emissions
will exceed the official limits.
MIL lights up
Higher exhaust emissions
Increased fuel consumption
Surge

Driver information
Warning light:
MIL ON

Service instruction
None