What does this code mean?
P0171/P0172 refer to bank 1; P0174/P0175 to bank 2. Lean or rich describes the controller's mixture assessment, not a direct measurement of a failed part. Compare fuel trims at idle and under load, inspect air and exhaust leaks, and test fuel supply or sensor readings using vehicle-specific limits.
Sources and interpretation [1]
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer communications
16Original wording in English
FORD
Reported code forms P0171
This article supersedes TSB 23-2195 to update the labor times from M-time to fixed time. Some of the vehicles listed in the Model statement above may exhibit an illuminated MIL in the instrument panel cluster (IPC) with…
FORD
Reported code forms P0171
Some 2021-2023 F-150 vehicles equipped with a 3.3L engine may exhibit an illuminated MIL in the instrument panel cluster (IPC) with DTC P0171 stored in the powertrain control module (PCM). This may be due to the…
FORD
Reported code forms P0171
Some 2021-2023 F-150 vehicles equipped with a 3.3L engine may exhibit an illuminated MIL in the instrument panel cluster (IPC) with DTC P0171 stored in the powertrain control module (PCM). This may be due to the…
FORD
Reported code forms P0171
Some 2019-2021 F-150 vehicles built on or before 04-Mar-2021 and equipped with a 5.0L engine may experience an illuminated malfunction indicator lamp (MIL) and diagnostic trouble codes (DTC) P0171, P0172, P0174, P0175,…
FORD
Reported code forms P0171
Some 2019-2020 F-150 vehicles equipped with a 5.0L flex fuel engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P0171, P0172, P0174 and/or P0175. This may be due to…
FORD
Reported code forms P0171
Some 2021 F-150 vehicles equipped with a 5.0L engine and built on or before 04-Mar-2021 may experience an illuminated malfunction indicator lamp (MIL) and diagnostic trouble codes (DTC) P0364, P060B, P062B, P164C,…
Check vehicle applicability
14A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Ford | F-150 | 2023 |
| Ford | F-150 | 2022 |
| Ford | F-150 | 2021 |
| Ford | F-150 | 2020 |
| Ford | F-150 | 2019 |
| Ford | F-150 | 2018 |
| Ford | F-150 | 2005 |
| Ford | F-150 | 2003 |
| Ford | F-150 | 2002 |
| Ford | F-150 | 2001 |
| Ford | F-150 | 2000 |
| Ford | F-150 | 1999 |
Historical records · 7 · Historical vehicle association; OBD-II compatibility is not established by this record.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Sources and interpretation
These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.
- 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗
Ford Motor Company · PDF page(s) 21, 22 ·
Source check date · 2026-10-27
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.