AutoCodes – Saturn – P0174 Saturn

P0174 Saturn Code - Fuel Trim System Lean Bank 2

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: P0174 Saturn indicates Fuel Trim System Lean Bank 2.
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 26,249

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 Aug 21, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0174 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 P0174 Saturn - Fuel Trim System Lean Bank 2 - AutoCodes.com — P0174 Saturn Code - Fuel Trim System Lean Bank 2

What does this mean?

What are the Possible Causes of the DTC P0174 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

How to Fix the DTC P0174 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 P0174 code means that more air than gasoline is detected in the exhaust gases exiting the combustion chamber. If the P0174 is set in along with the P0171 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 P0174

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 P0174

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0174 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 P0174 Saturn Code

1. What are the common symptoms of OBDII code P0174 on a Saturn indicating a Fuel Trim System Lean Bank 2 issue?

- Common symptoms include rough idling, poor acceleration, decreased fuel efficiency, and potential engine misfires.

2. What are the possible causes of the OBDII code P0174 Fuel Trim System Lean Bank 2 on a Saturn?

- Causes can include a vacuum leak, faulty oxygen sensor, clogged fuel filter, malfunctioning mass airflow sensor, or issues with the fuel injectors.

3. How can I diagnose the OBDII code P0174 on my Saturn related to a lean fuel trim system on Bank 2?

- Diagnose by checking for vacuum leaks, inspecting the oxygen sensor, testing the mass airflow sensor, examining the fuel filter, and confirming proper fuel injector function.

4. Can a dirty air filter trigger the OBDII code P0174 Fuel Trim System Lean Bank 2 on a Saturn?

- Yes, a dirty air filter can disrupt the air-fuel mixture, potentially causing a lean condition that triggers the P0174 code.

5. Is it safe to drive my Saturn with the OBDII code P0174 indicating a Fuel Trim System Lean Bank 2 issue?

- It is not recommended to drive for an extended period with this code as it can lead to further damage and decreased performance.

6. How can I repair the OBDII code P0174 Fuel Trim System Lean Bank 2 on my Saturn?

- Repair options may include fixing vacuum leaks, replacing the oxygen sensor, cleaning or replacing the mass airflow sensor, changing the fuel filter, or servicing the fuel injectors.

7. Will resetting the OBDII code P0174 on my Saturn resolve the Fuel Trim System Lean Bank 2 problem?

- Resetting the code may temporarily clear the warning, but if the underlying issue causing the lean condition is not addressed, the code is likely to reappear.

8. Can a failing fuel pump cause the OBDII code P0174 to be triggered on a Saturn?

- Yes, a failing fuel pump can disrupt the fuel delivery, leading to a lean condition and triggering the P0174 code.

9. How can I prevent the recurrence of the OBDII code P0174 Fuel Trim System Lean Bank 2 on my Saturn in the future?

- Regular maintenance, timely replacement of filters and sensors, addressing any issues promptly, and using quality fuel can help prevent the code from reoccurring.

10. Are there any software updates or recalls related to the OBDII code P0174 on Saturn vehicles?

- Check with a Saturn dealership or authorized service center to inquire about any software updates or recalls specifically related to the P0174 code for your vehicle model.