BMW DTC P2251 – O2 Sensor Negative Current Control Circuit/Open (Bank 1 Sensor 1)
DTC P2251 meaning on BMW
DTC P2251 for BMW refers to the O2 Sensor Negative Current Control Circuit/Open on Bank 1 Sensor 1. This diagnostic trouble code indicates that there is an open circuit or a fault in the negative current control circuit of the oxygen sensor located in the exhaust system of the engine bank 1.
BMW DTC P2251 symptoms
Symptoms of DTC P2251 on a BMW may include:
- Check Engine Light (CEL) illuminated on the dashboard
- Decreased fuel efficiency
- Engine running rough or misfiring
- Reduced engine performance
BMW DTC P2251 causes
Common causes of DTC P2251 on a BMW include:
- Faulty oxygen sensor (Bank 1 Sensor 1)
- Open circuit in the negative current control circuit
- Wiring or connector issues in the oxygen sensor circuit
- ECU (Engine Control Unit) malfunction
BMW DTC P2251 seriousness
DTC P2251 should not be ignored as it can lead to poor engine performance and increased emissions. Driving with this fault may cause further damage to the engine and catalytic converter over time.
How to diagnose DTC P2251 on BMW
To diagnose DTC P2251 on a BMW, you can follow these steps:
- Use an OBD-II scanner to retrieve the fault codes and check for DTC P2251.
- Inspect the wiring and connectors of the Bank 1 Sensor 1 oxygen sensor for any visible damage or corrosion.
- Test the oxygen sensor using a multimeter to check for proper resistance and voltage readings.
- Check the negative current control circuit for continuity and proper connection.
- Consult the BMW service manual for specific diagnostic procedures related to DTC P2251.
How to fix DTC P2251 on BMW
To fix DTC P2251 on a BMW, you can try the following solutions:
- Replace the Bank 1 Sensor 1 oxygen sensor if it is faulty.
- Repair any damaged wiring or connectors in the negative current control circuit.
- Reset the ECU by disconnecting the battery for a few minutes to clear the fault code.
- Perform a road test to ensure the issue has been resolved.
How to erase DTC P2251 on BMW
To erase DTC P2251 on a BMW, you can use an OBD-II scanner to clear the fault code after the underlying issue has been fixed. Once the fault code is cleared, the Check Engine Light should turn off. Make sure to verify that the issue has been resolved before clearing the code.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.