2019 BMW 128i Convertible (E88) L6-3.0L (N51) A L L Diagnostic Trouble Codes ( DTC ): Manufacturer Code Charts Page 156
Action in service
1. Visual inspection of wires, DME plug and O2 sensor for
damage
2. Check wires
3. Check plug-in connections DME <=> Wiring harness
<=> Downstream O2 sensor behind catalyst for Bank 1
4. Replace O2 sensor
5. Replace DME
Fault effect and breakdown warning
Driver information
Warning light:
MIL ON
Service instruction
none
2C9F - P0056 (DME)
2C9F - P0056
Information saved in
DME
Fault code
2C9F - P0056
Fault text
Oxygen sensor heating behind catalytic converter 2,
activation
Fault description
HO2S Heater Control Circuit (Bank 2 Sensor 2)
Condition for fault identification
Test condition:
Driver circuit diagnosis for O2 sensor heater
UBatt > 10V
Sensors installed
No fault memories
Terminal condition: Terminal 15, engine on
Voltage condition:
none
Condition for fault memory entry
Active immediately after terminal 15 change; electr. faults
entered within a few seconds
Action in service
1. Visual inspection of wiring, DME plug and O2 sensor for
damage
2. Inspect wiring
3. Check plug-in connections DME <=> Wiring harness
<=> downstream (post-cat) O2 sensor for Bank 2 precatalyst
4. Replace O2 sensor
5. Replace DME
Fault effect and breakdown warning
