AutoCodesGMC – P2049 2018 GMC Sierra

P2049 2018 GMC Sierra Code - Reductant Injector Control Circuit High Voltage

Quick Answer

The Reductant Injector is a component of selective catalytic reduction system used to dose the reductant fluid to the exhaust gas and participate in the reduction reactions. Common causes include Faulty Reductant Injector, Reductant Injector harness is open or shorted, Reductant Injector 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
P2049 2018 GMC Sierra indicates Reductant Injector Control Circuit High Voltage.
Common causes
Common causes include Faulty Reductant Injector, Reductant Injector harness is open or shorted, Reductant Injector 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.
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 165
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Oct 01, 2022
💬 Need more help? Ask Coddy for instant answers — it's free!

Code P2049 2018 GMC Sierra Description

The Reductant Injector is a component of selective catalytic reduction system used to dose the reductant fluid to the exhaust gas and participate in the reduction reactions. The Engine Control Module (ECM) calculates the injection time of the reductant injector based on the measurement of the NOx sensors. To activate the injector the ECM supplies a PWM signal to the high control circuit and the low control circuit is always commanded ON. The Diagnostic Trouble Code (DTC) will be set when the Reductant Control Module detects a short to voltage in the low control circuit.
OBDII Code P2049 2018 GMC Sierra - Reductant Injector Control Circuit High Voltage - AutoCodes.com
P2049 2018 GMC Sierra Code - Reductant Injector Control Circuit High Voltage

What are the Possible Causes of the DTC P2049 2018 GMC Sierra?

  • Faulty Reductant Injector
  • Reductant Injector harness is open or shorted
  • Reductant Injector circuit poor electrical connection
  • Faulty Engine Control Module (ECM)

How to Fix the DTC P2049 2018 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.

Code Tech Notes

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2049 2018 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 P2049 2018 GMC Sierra code?

Need more information on how to fix the P2049 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P2049 2018 GMC Sierra 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 P2049 2018 GMC Sierra Code

1. What does the OBDII code P2049 indicate on a 2018 GMC Sierra?

The code P2049 on a 2018 GMC Sierra indicates a problem with the reductant injector control circuit, specifically that the voltage in the circuit is higher than expected.

2. What symptoms might I notice if my 2018 GMC Sierra has the P2049 code?

Symptoms can include a check engine light, poor engine performance, increased emissions, and possibly a strong smell of ammonia from the exhaust.

3. What components are involved in causing the P2049 code in a 2018 GMC Sierra?

The components involved typically include the reductant injector, wiring harness, and the engine control module (ECM) that manages the circuit.

4. How can I fix the code P2049 in my 2018 GMC Sierra?

Fixing this code may involve inspecting and possibly replacing the reductant injector, repairing or replacing damaged wires or connectors in the control circuit, or updating or replacing the ECM if faulty.

5. What causes the reductant injector control circuit to have high voltage in a 2018 GMC Sierra?

Causes could include a faulty reductant injector, shorted wiring, poor connections, or a malfunctioning engine control module.

6. Is it safe to drive my 2018 GMC Sierra with the P2049 code?

While you may be able to drive for a short period, it’s not recommended as it can lead to further damage to the vehicle's emission system and potentially affect engine performance and efficiency.

7. How urgent is it to repair a P2049 code on a 2018 GMC Sierra?

It is fairly urgent to address this issue to prevent further damage to the vehicle's emission system and to ensure the vehicle remains compliant with emission standards.

8. Can the P2049 code affect the fuel economy of my 2018 GMC Sierra?

Yes, this code can affect fuel economy. The improper function of the reductant injector can lead to inefficient engine operation and increased fuel consumption.

9. What tools are needed to diagnose the P2049 code on a 2018 GMC Sierra?

Diagnosing this code typically requires an OBDII scanner to read the code and live data, a multimeter for checking voltages and resistances in the circuit, and possibly a scan tool for more in-depth analysis of ECM operations.

10. Could the P2049 code come back after it is cleared on my 2018 GMC Sierra?

Yes, if the underlying issue is not properly addressed, the code is likely to reappear. It’s important to perform a thorough diagnosis and repair to ensure the problem is fully resolved.

Discuss the causes and fixes for P2049 2018 GMC Sierra OBDII Code

Code P2049 2018 GMC Sierra comments

No comments found for this page.

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