Engine-CodesGMC – P1143 GMC

P1143 GMC Code - HO2S Bank 1 Sensor 3 Lean System or Low Voltage

Quick Answer

When the diagnostic trouble code P1143 appears on a GMC vehicle, it indicates an issue with the HO2S (Heated Oxygen Sensor) Bank 1 Sensor 3. Common causes include Faulty HO2S Bank 1 Sensor 3, Vacuum leak in the intake system, Clogged fuel injector. 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
P1143 GMC indicates HO2S Bank 1 Sensor 3 Lean System or Low Voltage.
Common causes
Common causes include Faulty HO2S Bank 1 Sensor 3, Vacuum leak in the intake system, Clogged fuel injector.
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.
Table of contents Created and updated by William Orellana on Sep 10, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P1143 GMC Description

When the diagnostic trouble code P1143 appears on a GMC vehicle, it indicates an issue with the HO2S (Heated Oxygen Sensor) Bank 1 Sensor 3. Specifically, the code signals a lean air/fuel mixture in the engine or low voltage from the sensor. This can have a significant impact on the vehicle's performance and emissions output. The oxygen sensor plays a crucial role in monitoring the oxygen levels in the exhaust gases, which helps the engine control module adjust the air/fuel mixture for optimal combustion.

OBDII Code P1143 GMC - HO2S Bank 1 Sensor 3 Lean System or Low Voltage
P1143 GMC Code - HO2S Bank 1 Sensor 3 Lean System or Low Voltage

Common Causes of P1143 GMC

  1. Faulty HO2S Bank 1 Sensor 3
  2. Vacuum leak in the intake system
  3. Clogged fuel injector
  4. Malfunctioning fuel pressure regulator
  5. Issues with the engine control module

Symptoms of P1143 GMC

  1. Decreased fuel efficiency
  2. Engine misfires or hesitation
  3. Rough idling or stalling
  4. Check Engine Light illuminated
  5. Increased emissions output

How to Fix P1143 GMC

  1. Retrieve the specific trouble code using an OBD-II scanner to confirm P1143.
  2. Inspect the HO2S Bank 1 Sensor 3 for any visible damage or contamination.
  3. Test the sensor's voltage output using a multimeter to determine if it is within specifications.
  4. Replace the HO2S Bank 1 Sensor 3 if it is faulty, following the manufacturer's instructions.
  5. Clear the trouble code and test drive the vehicle to ensure the issue has been resolved.

Cost to Fix P1143 GMC

The typical repair costs for addressing the P1143 code on a GMC vehicle can range from $150 to $400, depending on the cost of the oxygen sensor and labor charges. It's important to note that diagnosis time and labor rates at auto repair shops can vary, with hourly rates typically ranging between $80 and $150. Factors such as the vehicle make and model, location, and engine type can also influence the final repair costs. It's advisable to obtain quotes from multiple repair shops to compare prices and ensure a fair estimate.

Need more information about the P1143 GMC code?

Need more information on how to fix the P1143 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1143 GMC code diagnosed by a professional: Find a repair shop in your area

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 P1143 GMC Code

No Frequently Asked Questions about P1143 GMC Code found.

Discuss the causes and fixes for P1143 GMC OBDII Code

Code P1143 GMC comments

No comments found for this page.