AutoCodes – Chevrolet – P0171 2006 Chevrolet Trailblazer

P0171 2006 Chevrolet Trailblazer Code - Fuel Trim System Lean Bank 1

Quick Answer

The Engine Control Module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Common causes include Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring. 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 2006 Chevrolet Trailblazer indicates Fuel Trim System Lean Bank 1.
Common causes: Common causes include Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring.
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 27,956

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 Dec 12, 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 2006 Chevrolet Trailblazer Description

The Engine Control Module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open Loop and Closed Loop. During Open Loop, the ECM determines fuel delivery based on sensor signals without heated oxygen sensor (HO2S) input. During Closed Loop, the ECM adds HO2S inputs to calculate the short and long term fuel trim (FT) adjustments. If the HO2S indicates a lean condition, the fuel trim values will be above 0 percent. If the HO2S indicates a rich condition, the FT values will be below 0 percent. The short term FT values change rapidly in response to the HO2S voltage signals. The long term FT makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1.

OBDII Code P0171 2006 Chevrolet Trailblazer - Fuel Trim System Lean Bank 1 - AutoCodes.com — P0171 2006 Chevrolet Trailblazer Code - Fuel Trim System Lean Bank 1

What does this mean?

What are the Possible Causes of the DTC P0171 2006 Chevrolet Trailblazer?

Intake air leaks
Faulty front heated oxygen sensor
Ignition misfiring
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Faulty Mass Air Flow (MAF) sensor
Incorrect Positive Crankcase Ventilation (PCV) hose connection

How to Fix the DTC P0171 2006 Chevrolet Trailblazer?

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

If the P0171 is combined with the P0174 code, it's very 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 air flow meter. If the problem persists the front oxygen (O2) sensor may need to be replaced.

2006 Trailblazer P0171

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0171 2006 Chevrolet Trailblazer 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 2006 Chevrolet Trailblazer Code

1. What are the common symptoms of OBDII code P0171 on a 2006 Chevrolet Trailblazer?

- Common symptoms include rough idling, poor acceleration, decreased fuel efficiency, and the illumination of the check engine light.

2. What does the OBDII code P0171 on a 2006 Chevrolet Trailblazer indicate?

- The code P0171 indicates that the fuel trim system on Bank 1 is operating too lean, meaning there is too much air and not enough fuel in the fuel mixture.

3. What are the possible causes of OBDII code P0171 on a 2006 Chevrolet Trailblazer?

- Common causes include a vacuum leak, faulty oxygen sensor, clogged fuel filter, dirty mass airflow sensor, or a failing fuel pump.

4. How can I diagnose the cause of OBDII code P0171 on a 2006 Chevrolet Trailblazer?

- You can diagnose the issue by checking for vacuum leaks, testing the oxygen sensor, inspecting the fuel filter, cleaning the mass airflow sensor, and checking the fuel pump's pressure.

5. Can driving with OBDII code P0171 on a 2006 Chevrolet Trailblazer cause further damage?

- Continuing to drive with the code P0171 may lead to engine damage over time, as the engine is running too lean, which can affect its performance and longevity.

6. How can I repair OBDII code P0171 on a 2006 Chevrolet Trailblazer?

- Repair methods may include fixing vacuum leaks, replacing the oxygen sensor, cleaning or replacing the mass airflow sensor, changing the fuel filter, or inspecting the fuel pump for issues.

7. Is it safe to continue driving my 2006 Chevrolet Trailblazer with OBDII code P0171?

- It is not recommended to continue driving with the code P0171 on your Trailblazer, as it can lead to further engine problems and potential safety hazards.

8. Can a dirty air filter cause OBDII code P0171 on a 2006 Chevrolet Trailblazer?

- A dirty air filter can contribute to a lean fuel mixture, which may trigger the code P0171. It's important to check and replace the air filter if necessary.

9. How long does it take to fix OBDII code P0171 on a 2006 Chevrolet Trailblazer?

- The time to fix the code P0171 can vary depending on the underlying cause. Simple repairs like replacing a sensor may take less than an hour, while more complex issues may require several hours of work.

10. Will resetting the check engine light resolve OBDII code P0171 on a 2006 Chevrolet Trailblazer?

- Resetting the check engine light may temporarily turn it off, but it will not fix the underlying issue causing the code P0171. It's important to diagnose and repair the problem to prevent it from reoccurring.