AutoCodes – GMC – U029E 2015 GMC Sierra

U029E 2015 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 2015 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 265

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
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Code U029E 2015 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 2015 GMC Sierra - Lost Communication with NOX Sensor Module 2 Malfunction - AutoCodes.com — U029E 2015 GMC Sierra Code - Lost Communication with NOX Sensor Module 2 Malfunction

What does this mean?

What are the Possible Causes of the DTC U029E 2015 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 2015 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 2015 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 2015 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 2015 GMC Sierra Code

1. What are the common symptoms of OBDII code U029E in a 2015 GMC Sierra?

The common symptoms of code U029E include the check engine light coming on, reduced engine performance, and issues with the vehicle's emissions system.

2. What does the OBDII code U029E "Lost Communication with NOX Sensor Module 2 Malfunction" mean for a 2015 GMC Sierra?

This code indicates a communication problem between the vehicle's onboard computer and the NOX (nitrogen oxide) sensor module 2, which can affect the monitoring and control of emissions.

3. What are the possible causes of U029E in a 2015 GMC Sierra?

Possible causes of U029E can include a faulty NOX sensor module 2, damaged wiring or connectors, a software glitch in the vehicle's computer system, or issues with the power supply to the sensor module.

4. How can I diagnose the U029E code in my 2015 GMC Sierra?

Diagnosing the U029E code typically involves using an OBDII scanner to retrieve the specific fault codes, checking the wiring and connectors associated with the NOX sensor module 2, and testing the sensor module itself for proper functionality.

5. Can I continue driving my 2015 GMC Sierra with the U029E code present?

It is not recommended to continue driving with the U029E code active, as it can lead to potential issues with emissions control and overall engine performance. It's best to address the problem promptly.

6. How can I repair the U029E code in my 2015 GMC Sierra?

Repairing the U029E code may involve replacing the NOX sensor module 2 if it's found to be faulty, repairing any damaged wiring or connectors, updating the vehicle's software if necessary, and ensuring proper power supply to the sensor module.

7. Will resetting the trouble codes make the U029E code go away in my 2015 GMC Sierra?

Simply resetting the trouble codes may temporarily clear the check engine light, but if the underlying issue causing the U029E code is not addressed, the code is likely to reappear once the vehicle's computer detects the problem again.

8. How much does it cost to repair the U029E code in a 2015 GMC Sierra?

The cost of repairing the U029E code can vary depending on the specific cause of the issue, the labor rates of the repair shop, and the cost of any replacement parts needed. It's best to consult with a mechanic for an accurate estimate.

9. Can a DIY enthusiast fix the U029E code in a 2015 GMC Sierra?

While some aspects of diagnosing and repairing the U029E code may be feasible for experienced DIY enthusiasts, dealing with advanced electrical systems and emissions components like the NOX sensor module 2 may require specialized tools and expertise best handled by a professional mechanic.

10. How often does the U029E code occur in 2015 GMC Sierra vehicles?

The U029E code "Lost Communication with NOX Sensor Module 2 Malfunction" is relatively uncommon but can occur in 2015 GMC Sierra vehicles due to various factors like sensor failures, wiring issues, or software malfunctions.