HomeBrandsBMWSUVsp0171
p0171
Moderate
BMW · SUVs
System Too Lean Bank 1
Quick Answer
Error code P0171 on your BMW SUVs means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
X1 M35i 2024X1 xDrive28i 2024X3 M 2024X3 M40i 2024X3 xDrive30i 2024X5 M 2024X5 M60i 2024X5 xDrive40i 2024X5 xDrive50e 2024X6 M 2024X6 M60i 2024X6 xDrive40i 2024X7 M60i 2024X7 xDrive40i 2024iX M60 2024iX xDrive50 2024X1X3 MX3X5 MX5X6X7iX
Likely Causes
  1. Vacuum leak at intake manifold or boost hoses
  2. Faulty mass airflow (MAF) sensor
  3. Clogged or failing fuel injectors
  4. Weak fuel pump or restricted fuel filter
  5. Cracked PCV valve hose or oil separator failure
How to Fix It
1
Inspect intake manifold and all vacuum/boost hoses for cracks or disconnections
2
Clean or replace the MAF sensor
3
Check fuel pressure at the fuel rail with a gauge
4
Inspect fuel injectors for proper operation and spray pattern
5
Check PCV system and oil separator for failures common in BMW SUVs
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
MAF sensor
Vacuum hoses
Fuel injectors
Oil separator (CCV)
Related Error Codes
P0174P0300P0301P0335P0340
Video Guides
Loading video guides…
Search more on YouTube →