AutoCodes – GMC – P0490 2014 GMC Sierra

P0490 2014 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 2014 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 223
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 2014 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 2014 GMC Sierra - Exhaust Gas Recirculation Motor Control Circuit High Voltage - AutoCodes.com
P0490 2014 GMC Sierra Code - Exhaust Gas Recirculation Motor Control Circuit High Voltage

What are the Possible Causes of the DTC P0490 2014 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 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 P0490 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 P0490 2014 GMC Sierra code?

Need more information on how to fix the P0490 2014 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 2014 GMC Sierra Code

1. What does the P0490 code mean on a 2014 GMC Sierra?

The P0490 code indicates a high voltage issue in the Exhaust Gas Recirculation (EGR) motor control circuit, which may prevent proper operation of the EGR system.

2. What are the symptoms of a P0490 code in a 2014 GMC Sierra?

Symptoms can include a check engine light, reduced engine performance, rough idling, poor fuel efficiency, or increased emissions.

3. What causes the P0490 code to appear?

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

4. Can I drive my 2014 GMC Sierra with a P0490 code?

While the vehicle may still run, driving with this code can lead to diminished performance, increased emissions, and potential damage to other components if not addressed promptly.

5. How is the P0490 code diagnosed?

A mechanic will use an OBDII scanner to confirm the code, inspect EGR system wiring and connectors, test the EGR valve, and check for carbon buildup or other obstructions.

6. How do I fix the P0490 code on a 2014 GMC Sierra?

Repairs may include cleaning or replacing the EGR valve, repairing damaged wiring or connectors, or replacing the EGR control module if faulty.

7. Can a dirty EGR valve trigger a P0490 code?

Yes, carbon buildup in the EGR valve can cause it to stick, leading to abnormal voltage signals and triggering the P0490 code.

8. How much does it cost to fix a P0490 code on a 2014 GMC Sierra?

Repair costs can vary but typically range from $150 to $500, depending on whether cleaning or part replacement is needed.

9. Is the P0490 code related to emissions issues?

Yes, a malfunctioning EGR system can increase nitrogen oxide emissions and may cause the vehicle to fail an emissions test.

10. Can I reset the P0490 code without repairs?

You can clear the code with an OBDII scanner, but if the underlying issue isn't fixed, the code will likely return.

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