p0171
Moderate
Mercedes-Benz · SUVs
System Too Lean Bank 1
Quick Answer
Error code P0171 on your Mercedes-Benz SUVs means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
X243X247X254V167X167AMG GLB35 4MATIC 2024AMG GLC43 4MATIC 2024AMG GLC63 S 2024AMG GLE53 4MATIC+ 2024AMG GLE63 S 2024AMG GLS63 2024EQB 250+ 2024EQB 300 4MATIC 2024EQB 350 4MATIC 2024GLB250 2024GLB250 4MATIC 2024GLC300 2024GLC300 4MATIC 2024GLE350 4MATIC 2024GLE450 4MATIC 2024GLS450 4MATIC 2024GLS580 4MATIC 2024Maybach GLS600 2024
Likely Causes
How to Fix It
1
Retrieve freeze frame data to determine operating conditions when the code set
2
Perform a smoke test on the intake system including turbo boost hoses
3
Clean or replace the MAF sensor and clear the code
4
Test fuel pressure at idle and under load with a fuel pressure gauge
5
Inspect intake air ducts and connections for cracks or loose clamps
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
Intake air duct
Vacuum hoses
Fuel filter
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