AutoCodes – Saturn – P0171 Saturn

P0171 Saturn 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 Saturn 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 55,290

How popular is this code, among other codes? Medium

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 May 29, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0171 Saturn 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 Saturn - Fuel Trim System Lean Bank 1 - AutoCodes.com — P0171 Saturn Code - Fuel Trim System Lean Bank 1

What does this mean?

What are the Possible Causes of the DTC P0171 Saturn?

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 Saturn?

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.

Click Here to Learn What is Bank 1 and Bank 2

There are Factory Service Bulletins for the following Saturn models:
2000-2008 Saturn All Models
2000-2008 Saturn Factory Service Bulletin OBDII Code P0171

2000 Saturn L-Series
2001 Saturn L-Series
2002 Saturn L-Series
2003 Saturn L-Series
2000-2003 Saturn L-Series Factory Service Bulletin OBDII Code P0171

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0171 Saturn 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.

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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 Saturn Code

1. What does OBDII code P0171 for a Saturn indicate?

The OBDII code P0171 for a Saturn indicates a "Fuel Trim System Lean Bank 1" condition, meaning that the engine is receiving too much air or too little fuel.

2. What are the common symptoms of OBDII code P0171 in a Saturn?

Common symptoms of OBDII code P0171 in a Saturn include rough idling, poor acceleration, decreased fuel efficiency, and the illumination of the check engine light.

3. What are the possible causes of OBDII code P0171 in a Saturn?

Possible causes of OBDII code P0171 in a Saturn include a vacuum leak, faulty oxygen sensor, clogged fuel filter, fuel injector issues, or a malfunctioning mass airflow sensor.

4. How can I diagnose the source of OBDII code P0171 in my Saturn?

To diagnose the source of OBDII code P0171 in your Saturn, you can perform a visual inspection for leaks, check the oxygen sensor readings, test the fuel pressure, inspect the air intake system, and scan for any other related trouble codes.

5. Can a dirty air filter trigger OBDII code P0171 in a Saturn?

Yes, a dirty or clogged air filter can restrict airflow to the engine, causing a lean fuel mixture and triggering OBDII code P0171 in a Saturn.

6. Is it safe to continue driving my Saturn with OBDII code P0171?

It is not recommended to continue driving your Saturn with OBDII code P0171, as a lean fuel mixture can lead to engine damage over time. It is best to address the issue promptly.

7. How can I repair OBDII code P0171 in my Saturn?

To repair OBDII code P0171 in your Saturn, you may need to replace the oxygen sensor, clean or replace the mass airflow sensor, fix any vacuum leaks, replace the fuel filter, or address any other identified issues causing the lean fuel condition.

8. Can a bad fuel pump cause OBDII code P0171 in a Saturn?

Yes, a weak or failing fuel pump can cause insufficient fuel delivery to the engine, leading to a lean fuel mixture and triggering OBDII code P0171 in a Saturn.

9. Will resetting the check engine light resolve OBDII code P0171 in my Saturn?

Resetting the check engine light may temporarily turn it off, but it will not fix the underlying issue causing OBDII code P0171 in your Saturn. It is important to diagnose and repair the problem to prevent further issues.

10. How can I prevent OBDII code P0171 from occurring in my Saturn in the future?

To prevent OBDII code P0171 from occurring in your Saturn in the future, it is essential to perform regular maintenance, such as replacing the air filter, fuel filter, and oxygen sensor as recommended, and addressing any issues promptly to maintain proper fuel mixture ratios.