2019 BMW 128i Convertible (E88) L6-3.0L (N51) A L L Diagnostic Trouble Codes ( DTC ): Manufacturer Code Charts Page 135
Action in service
none
Fault effect and breakdown warning
Driver information
Warning light:
none
Service instruction
none
(DME) Condition For Fault Memory Entry - 1
2C3D - P112C
Information saved in
DME
Fault code
2C3D - P112C
Fault text
Oxygen sensor before catalytic converter, line fault
Fault description
O2 Sensor Negative Current or Positive Current Control
Circuit/Open (Bank 1 Sensor 1)
Condition for fault identification
Test condition:
O2 sensor wiring monitor
O2 sensor signal freezes.
No fault memories
Drive at 50 - 80 km/h at moderate engine speed
Terminal condition: Terminal 15, engine on
Voltage condition:
none
Condition for fault memory entry
Voltage seizes at 2V (Lambda = 1) OR voltage < 2.1 V with
overrun injection deactivation active
Action in service
1. Visual inspection of wires, DME plug and O2 sensor for
damage
2. Inspect wires
3. Check plug-in connections DME <=> Wiring harness
<=> Upstream (pre-cat) O2 sensor for Bank 1 (water or
corrosion in plug?) => Repeatedly remove the plug and then
reconnect it FIRMLY)
4. Check catalytic converter (is FSD lean fault entered for
the other bank?)
5. Piston rings, injectors, positive crankcase ventilation OK?
FSD fault? Then continue there!
6. Replace O2 sensor
7. Replace DME
Fault effect and breakdown warning
