AutoCodes – Chevrolet – P0171 2018 Chevrolet Silverado

P0171 2018 Chevrolet Silverado Code - Fuel Trim System Lean Bank 1

Quick Answer

The Engine Control Module (ECM) controls a Closed Loop air/fuel metering system to provide the best possible combination of drivability, fuel economy, and emission control. Common causes include Dirty or Restricted Air Filter, Dirty or Faulty Mass Air Flow (MAF) Sensor, Intake Air Leaks. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0171 2018 Chevrolet Silverado indicates Fuel Trim System Lean Bank 1.
Common causes: Common causes include Dirty or Restricted Air Filter, Dirty or Faulty Mass Air Flow (MAF) Sensor, Intake Air Leaks.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,327

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 23, 2023

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0171 2018 Chevrolet Silverado Description

The Engine Control Module (ECM) controls a Closed Loop air/fuel metering system to provide the best possible combination of drivability, fuel economy, and emission control. The ECM monitors the Heated Oxygen Sensor (HO2S) signal voltage and adjusts the fuel delivery based on the signal voltage while in Closed Loop. A change made to the fuel delivery changes the long and short-term fuel trim values. The short-term fuel trim values change rapidly in response to the HO2S signal voltages. These changes fine-tune the engine fueling. The long-term fuel trim values change in response to trends in the short-term fuel trim. The long-term fuel trim makes coarse adjustments to fueling to re-center and restore control to short-term fuel trim. The ideal fuel trim values are around 0 %. A positive fuel trim value indicates that the ECM is adding fuel to compensate for a lean condition. A negative fuel trim value indicates that the ECM is reducing the amount of fuel to compensate for a rich condition. The Diagnostic Trouble Code (DTC) will be set when the average long-term fuel trim weighted average value is greater or less than a calibrated value.

OBDII Code P0171 2018 Chevrolet Silverado - Fuel Trim System Lean Bank 1 - AutoCodes.com — P0171 2018 Chevrolet Silverado Code - Fuel Trim System Lean Bank 1

What does this mean?

What are the Possible Causes of the DTC P0171 2018 Chevrolet Silverado?

Dirty or Restricted Air Filter
Dirty or Faulty Mass Air Flow (MAF) Sensor
Intake Air Leaks
Exhaust Gas Leaks
Fuel Contamination
Faulty or Clogged Fuel Injectors
Faulty Front Heated Oxygen Sensor
Ignition Misfiring
Low Fuel Pressure
Positive Crankcase Ventilation (PCV) Hose Leaks
Engine Control Temperature (ECT) inaccurate readings

How to Fix the DTC P0171 2018 Chevrolet Silverado?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The P0171 code means that more air than gasoline is detected in the exhaust gases exiting the combustion chamber. If the P0171 is set in along with the P0174 code, it is highly likely that the problem is caused by an intake leak. If there are no intake leaks, the next step is to replace the air filter and clean the Mass Air Flow (MAF) Sensor. If the problem persists the MAF or Front Heated Oxygen (O2) Sensor will need to be replaced.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0171 2018 Chevrolet Silverado code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0171 2018 Chevrolet Silverado code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0171 2018 Chevrolet Silverado Code

1. What does OBDII code P0171 mean for my 2018 Chevrolet Silverado?

- OBDII code P0171 on a 2018 Chevrolet Silverado indicates a lean condition in the fuel trim system on Bank 1.

2. What are the common symptoms of OBDII code P0171 on a 2018 Chevrolet Silverado?

- Common symptoms of P0171 include rough idle, reduced engine performance, hesitation during acceleration, and potential stalling.

3. What are the possible causes of OBDII code P0171 on a 2018 Chevrolet Silverado?

- Causes of P0171 can include a vacuum leak, faulty oxygen sensor, fuel delivery issues, intake air leaks, or a malfunctioning mass airflow sensor.

4. How can I diagnose the cause of OBDII code P0171 on my 2018 Chevrolet Silverado?

- Diagnosing P0171 may involve checking for vacuum leaks, inspecting the air intake system, testing the oxygen sensor, examining the fuel pressure, and scanning for other related trouble codes.

5. Can a dirty or clogged fuel filter trigger OBDII code P0171 on a 2018 Chevrolet Silverado?

- Yes, a dirty or clogged fuel filter can contribute to a lean condition, potentially triggering OBDII code P0171 on a 2018 Chevrolet Silverado.

6. Is it safe to continue driving my 2018 Chevrolet Silverado with OBDII code P0171 present?

- It is not recommended to ignore OBDII code P0171 as it can lead to poor engine performance and potential damage over time. It's advisable to address the issue promptly.

7. How can I reset OBDII code P0171 on my 2018 Chevrolet Silverado after making repairs?

- After addressing the underlying issue causing P0171, you can reset the code using an OBDII scanner or disconnecting the vehicle's battery for a few minutes.

8. Will a faulty catalytic converter trigger OBDII code P0171 on a 2018 Chevrolet Silverado?

- A faulty catalytic converter can contribute to a lean condition and trigger P0171, especially if left unresolved for an extended period.

9. Can extreme weather conditions affect the occurrence of OBDII code P0171 on a 2018 Chevrolet Silverado?

- Extreme weather conditions, such as very cold temperatures, can potentially exacerbate existing issues that lead to a lean fuel trim condition and trigger P0171.

10. Should I seek professional help to diagnose and repair OBDII code P0171 on my 2018 Chevrolet Silverado?

- If you are unsure about diagnosing or repairing P0171, it is recommended to seek the expertise of a qualified mechanic or service center to ensure the issue is properly addressed.