2AA3

2AA3 - P2243

Information saved in
DME

Fault code
2AA3 - P2243

Fault text
Oxygen sensor before catalytic converter, Nernst cable

Fault description
Pre-catalyst oxygen sensor, Nernst cable

Condition for fault identification
Test condition:
Engine running
Battery voltage: 10.7 V..16 V
No output driver circuit fault with sensor heater
No deactivation of pump voltage for oxygen sensor before
cat.
Terminal condition: none
Voltage condition:
none

Condition for fault memory entry
1 sec.

Action in service
Check wiring harness between DME and oxygen sensor in
front of catalyst; I_LSVR1
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