AutoCodes – GMC – U029E 2014 GMC Sierra

U029E 2014 GMC Sierra Code - Lost Communication with NOX Sensor Module 2 Malfunction

Quick Answer

The reductant system uses two Nitrogen Oxide (NOx) sensors to monitor the amount of NOx in the engine's exhaust gas. Common causes include Faulty Nitrogen Oxide (NOx) Sensor Module 2, Nitrogen Oxide Sensor Module 2 harness is open or shorted, Nitrogen Oxide Sensor Module 2 circuit poor electrical connection. 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: U029E 2014 GMC Sierra indicates Lost Communication with NOX Sensor Module 2 Malfunction.
Common causes: Common causes include Faulty Nitrogen Oxide (NOx) Sensor Module 2, Nitrogen Oxide Sensor Module 2 harness is open or shorted, Nitrogen Oxide Sensor Module 2 circuit poor electrical connection.
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 260

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Oct 18, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U029E 2014 GMC Sierra Description

The reductant system uses two Nitrogen Oxide (NOx) sensors to monitor the amount of NOx in the engine's exhaust gas. The first sensor is located at the outlet of the turbocharger and monitors the engine out NOx level. The second NOx sensor is located between the Selective Catalytic Reduction (SCR) and the Diesel Particulate Filter (DPF) and monitors NOx levels downstream of the SCR. The second NOx sensor also provides the Engine Control Module (ECM) with information on the exhaust oxygen level during DPF regeneration.
Each NOx sensor contains a sensing cell, a pumping cell, and a heater. A sample of exhaust gas passes through a diffusion gap between the sensing cell and the pumping cell. The NOx sensor maintains a constant reference voltage across the sensing cell. An electronic circuit within sensor controls the pump current through the pumping cell in order to maintain a constant voltage in the sensing cell. The amount of current required to maintain the reference voltage in the sensing cell is proportional to the concentration of NOx in the exhaust.
The ECM varies the amount of Diesel Exhaust Fluid (DEF) or reductant added by varying the reductant injector duty cycle in response to changes in engine exhaust out NOx levels. The smart NOx sensors consist of two components, the NOx module and the NOx sensor element that are serviced as a unit. A circuit or performance condition with a NOx sensor is detected by the NOx sensor module. The smart NOx sensor module communicates the condition to the ECM over the serial data line. The ECM sets a DTC when a serial data message is received from the NOx sensor module.

OBDII Code U029E 2014 GMC Sierra - Lost Communication with NOX Sensor Module 2 Malfunction - AutoCodes.com — U029E 2014 GMC Sierra Code - Lost Communication with NOX Sensor Module 2 Malfunction

What does this mean?

What are the Possible Causes of the DTC U029E 2014 GMC Sierra?

Faulty Nitrogen Oxide (NOx) Sensor Module 2
Nitrogen Oxide Sensor Module 2 harness is open or shorted
Nitrogen Oxide Sensor Module 2 circuit poor electrical connection

How to Fix the DTC U029E 2014 GMC Sierra?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U029E 2014 GMC Sierra 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 U029E 2014 GMC Sierra 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 U029E 2014 GMC Sierra Code

1. What are the common symptoms of the U029E OBDII code on a 2014 GMC Sierra?

The common symptoms include the check engine light illuminating, poor engine performance, decreased fuel efficiency, and potential issues with emissions.

2. What does the U029E code "Lost Communication with NOX Sensor Module 2 Malfunction" mean?

This code indicates that the vehicle's onboard diagnostic system has detected a communication problem with the NOx sensor module 2, which is responsible for monitoring nitrogen oxide levels in the exhaust system.

3. What are the possible causes of the U029E code on a 2014 GMC Sierra?

The possible causes include a faulty NOx sensor module 2, wiring or connection issues, a defective powertrain control module (PCM), or software glitches in the vehicle's computer system.

4. How can I diagnose the U029E code on my 2014 GMC Sierra?

Diagnosing the U029E code typically involves using a diagnostic scanner to retrieve the specific fault codes, checking the wiring and connections to the NOx sensor module 2, and testing the module itself for proper functionality.

5. Can I continue driving my 2014 GMC Sierra with the U029E code present?

It is not recommended to continue driving the vehicle with the U029E code active, as it can lead to further damage to the emissions system and potentially affect engine performance.

6. How can I repair the U029E code on my 2014 GMC Sierra?

Repairing the U029E code may involve replacing the NOx sensor module 2, repairing any damaged wiring or connections, reprogramming the PCM, or updating the vehicle's software to resolve communication issues.

7. Are there any DIY tips for addressing the U029E code on a 2014 GMC Sierra?

While some basic checks like inspecting wiring connections can be done by DIY enthusiasts, diagnosing and repairing the U029E code may require advanced automotive knowledge and specialized tools, so it is recommended to seek professional help.

8. How much does it typically cost to repair the U029E code on a 2014 GMC Sierra?

The cost of repairing the U029E code can vary depending on the specific underlying issue, but it may range from a few hundred dollars for minor repairs to over a thousand dollars for more complex problems like replacing the NOx sensor module.

9. Will resetting the check engine light make the U029E code go away on a 2014 GMC Sierra?

Resetting the check engine light may temporarily clear the code, but if the underlying issue causing the U029E code is not addressed, the code is likely to reappear once the vehicle's onboard diagnostic system runs its checks again.

10. Can a mechanic help me with diagnosing and repairing the U029E code on my 2014 GMC Sierra?

Yes, a qualified mechanic with experience in diagnosing and repairing OBDII codes like U029E can help identify the root cause of the issue and perform the necessary repairs to resolve the problem effectively.