BMW DTC P0155 – O2 Sensor Heater Circuit (Bank 2 Sensor 1)
DTC P0155 meaning on BMW
The Diagnostic Trouble Code (DTC) P0155 for BMW refers to an issue with the O2 Sensor Heater Circuit for Bank 2 Sensor 1. This code indicates that there is a malfunction in the heater circuit of the oxygen sensor located in the exhaust system of the vehicle.
BMW DTC P0155 symptoms
Symptoms of DTC P0155 on a BMW may include:
- Check Engine Light illuminated on the dashboard
- Poor fuel economy
- Engine running rough or misfiring
- Failed emissions test
BMW DTC P0155 causes
Common causes of DTC P0155 on a BMW include:
- Faulty O2 sensor heater circuit
- Wiring or connector issues in the O2 sensor circuit
- Blown fuse related to the O2 sensor heater
- ECU (Engine Control Unit) malfunction
BMW DTC P0155 seriousness
While DTC P0155 may not cause immediate drivability issues, it can lead to poor engine performance and increased emissions. Ignoring this code can result in decreased fuel efficiency and potential damage to the catalytic converter over time.
How to diagnose DTC P0155 on BMW
To diagnose DTC P0155 on a BMW, you can follow these steps:
- Use an OBD-II scanner to retrieve the specific fault code
- Inspect the wiring and connectors related to Bank 2 Sensor 1
- Check the fuse for the O2 sensor heater circuit
- Test the O2 sensor heater resistance with a multimeter
- Verify the ECU is sending the correct signals to the O2 sensor
How to fix DTC P0155 on BMW
To fix DTC P0155 on a BMW, you can try the following solutions:
- Replace the faulty O2 sensor with a new one
- Repair any damaged wiring or connectors in the O2 sensor circuit
- Replace the blown fuse related to the O2 sensor heater
- If the ECU is faulty, have it repaired or replaced by a professional
How to erase DTC P0155 on BMW
To erase DTC P0155 on a BMW, you can clear the code using an OBD-II scanner. After fixing the underlying issue that caused the code, you can reset the Check Engine Light and clear the DTC from the ECU’s memory.
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
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