GMC Sierra 1500 · Diagnostic Trouble Code
P0171 — System Too Lean (Bank 1)
Quick overview of P0171 on your GMC Sierra 1500. Read the full diagnosis guide, then find the repair guides for your vehicle below.
Repair guides that fix P0171
GMC Sierra 1500
2019-2024 GMC Sierra 1500 — Fuel Pump Replacement
How to test fuel delivery when pressure is suspect.
GMC Sierra 1500
2019-2024 GMC Sierra 1500 - Engine Air Filter Replacement
A restricted air filter can skew the air-fuel mixture.
GMC Sierra 1500
2019-2024 GMC Sierra 1500 — Check Engine Light / OBD2 Diagnosis
What that light means and what to check first.
General diagnostic information, not a factory service procedure. If you're unsure, have a qualified technician confirm the diagnosis before buying parts.