AutoCodes – GMC – P0490 2017 GMC Sierra

P0490 2017 GMC Sierra Code - Exhaust Gas Recirculation Motor Control Circuit High Voltage

Quick Answer

The Engine Control Module (ECM) supplies the Exhaust Gas Recirculation (EGR) valve with a 5 V reference circuit, a low reference circuit, an H-bridge motor directional control circuit, and a signal circuit. Common causes include Faulty Exhaust Gas Recirculation (EGR) Valve, Exhaust Gas Recirculation Valve harness is open or shorted, Exhaust Gas Recirculation Valve 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
P0490 2017 GMC Sierra indicates Exhaust Gas Recirculation Motor Control Circuit High Voltage.
Common causes
Common causes include Faulty Exhaust Gas Recirculation (EGR) Valve, Exhaust Gas Recirculation Valve harness is open or shorted, Exhaust Gas Recirculation Valve 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 187
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Jun 19, 2022
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Code P0490 2017 GMC Sierra Description

The Engine Control Module (ECM) supplies the Exhaust Gas Recirculation (EGR) valve with a 5 V reference circuit, a low reference circuit, an H-bridge motor directional control circuit, and a signal circuit. The EGR position sensor provides a signal voltage that changes relative to the EGR position. The EGR position sensor information is transmitted between the EGR valve and the ECM on the signal circuit. The Mass Air Flow (MAF) sensor signal is used by the ECM to detect the proper amount of EGR flow. The ECM will close the EGR valve, then open the EGR valve to 100%. The ECM will then calculate the MAF difference and determine if the proper EGR flow has been detected. The Diagnostic Trouble Code (DTC) will be set when the ECM detects a short to voltage on the control circuit for greater than 2.5 s.
OBDII Code P0490 2017 GMC Sierra - Exhaust Gas Recirculation Motor Control Circuit High Voltage - AutoCodes.com
P0490 2017 GMC Sierra Code - Exhaust Gas Recirculation Motor Control Circuit High Voltage

What are the Possible Causes of the DTC P0490 2017 GMC Sierra?

  • Faulty Exhaust Gas Recirculation (EGR) Valve
  • Exhaust Gas Recirculation Valve harness is open or shorted
  • Exhaust Gas Recirculation Valve circuit poor electrical connection
  • Faulty Engine Control Module (ECM)

How to Fix the DTC P0490 2017 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 P0490 2017 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 P0490 2017 GMC Sierra code?

Need more information on how to fix the P0490 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the 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 P0490 2017 GMC Sierra Code

1. What does the OBDII code P0490 mean on a 2017 GMC Sierra?

P0490 indicates a high voltage issue in the Exhaust Gas Recirculation (EGR) motor control circuit, suggesting a problem with the EGR system's functionality.

2. What are the common symptoms of code P0490 on a 2017 GMC Sierra?

Symptoms may include the check engine light turning on, reduced engine performance, rough idling, increased fuel consumption, or failed emissions tests.

3. What causes the P0490 code to appear on a 2017 GMC Sierra?

Common causes include a faulty EGR valve, damaged wiring or connectors in the EGR circuit, a failed EGR control module, or carbon buildup obstructing the EGR valve.

4. Can a dirty EGR valve cause the P0490 code on a 2017 GMC Sierra?

Yes, carbon buildup or clogging in the EGR valve can cause it to malfunction, leading to the P0490 code.

5. How do you diagnose code P0490 on a 2017 GMC Sierra?

Diagnosis involves scanning for codes, inspecting EGR wiring and connectors for damage, testing the EGR valve with a multimeter, and checking for carbon buildup.

6. Can you still drive a 2017 GMC Sierra with the P0490 code active?

While the vehicle may still be drivable, prolonged driving with this code can lead to reduced performance, higher emissions, and potential engine damage.

7. How do you fix the P0490 code on a 2017 GMC Sierra?

Repairs may include cleaning or replacing the EGR valve, repairing damaged wiring, replacing the EGR control module, or clearing carbon buildup in the system.

8. How much does it cost to repair the P0490 code on a 2017 GMC Sierra?

The cost depends on the issue. Cleaning the EGR valve may cost around $100-$200, while replacing it can range from $300-$500, including labor.

9. Can a faulty EGR valve trigger other codes along with P0490 on a 2017 GMC Sierra?

Yes, a faulty EGR valve may also trigger related codes like P0401 (EGR flow insufficient) or P0402 (EGR flow excessive).

10. How can you prevent the P0490 code on a 2017 GMC Sierra?

Regular maintenance, such as cleaning the EGR valve and inspecting wiring, can help prevent the buildup and electrical issues that lead to this code.

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