BMW DTC P0173 – Fuel Trim (Bank 2)
DTC P0173 meaning on BMW
The Diagnostic Trouble Code (DTC) P0173 for BMW indicates that the fuel trim on Bank 2 of the engine is too high. This means that the Engine Control Module (ECM) has detected that the air-fuel mixture is too rich on Bank 2, causing the fuel trim to exceed the specified limits.
BMW DTC P0173 symptoms
Symptoms of a DTC P0173 on a BMW may include:
- Check Engine Light (CEL) illuminated
- Decreased fuel efficiency
- Rough idling or stalling
- Black smoke from the exhaust
- Engine hesitation or misfiring
BMW DTC P0173 causes
Common causes of a DTC P0173 on a BMW include:
- Vacuum leaks
- Faulty oxygen sensor
- Dirty or clogged fuel injectors
- Fuel pressure regulator issues
- Intake air leaks
BMW DTC P0173 seriousness
While a DTC P0173 may not cause immediate engine failure, it can lead to decreased fuel efficiency and potential damage to the catalytic converter over time if left unresolved. It is important to address this issue promptly to prevent further complications.
How to diagnose DTC P0173 on BMW
To diagnose a DTC P0173 on a BMW, you can perform the following steps:
- Use an OBD-II scanner to retrieve the fault code and freeze frame data
- Inspect for any visible signs of vacuum leaks or damaged hoses
- Check the oxygen sensor readings and fuel trims using a diagnostic tool
- Clean or replace the fuel injectors if necessary
- Perform a smoke test to identify any intake air leaks
How to fix DTC P0173 on BMW
To fix a DTC P0173 on a BMW, you can try the following solutions:
- Repair any vacuum leaks and replace damaged hoses
- Replace the faulty oxygen sensor
- Clean or replace clogged fuel injectors
- Check and adjust the fuel pressure regulator
- Address any intake air leaks by repairing or replacing affected components
How to erase DTC P0173 on BMW
To erase a DTC P0173 on a BMW, you can use an OBD-II scanner to clear the fault code from the ECM’s memory. After fixing the underlying issue causing the DTC, you can reset the code to turn off the Check Engine Light and ensure the problem has been resolved.
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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