AutoCodes – Chevrolet – P0490 Chevrolet

P0490 Chevrolet 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 Chevrolet 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 1,240

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0490 Chevrolet 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 Chevrolet - Exhaust Gas Recirculation Motor Control Circuit High Voltage - AutoCodes.com — P0490 Chevrolet Code - Exhaust Gas Recirculation Motor Control Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0490 Chevrolet?

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 Chevrolet?

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 Chevrolet 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 Chevrolet code?

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

Need Help with the Code?

Get the P0490 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

P0490 2014 Chevrolet Silverado — Exhaust Gas Recirculation Motor Control Circuit High Voltage
P0490 2015 Chevrolet Silverado — Exhaust Gas Recirculation Motor Control Circuit High Voltage
P0490 2016 Chevrolet Silverado — Exhaust Gas Recirculation Motor Control Circuit High Voltage
P0490 2017 Chevrolet Silverado — Exhaust Gas Recirculation Motor Control Circuit High Voltage
P0490 2018 Chevrolet Silverado — Exhaust Gas Recirculation Motor Control Circuit High Voltage

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 Chevrolet Code

1. What are the common symptoms of OBDII code P0490 in a Chevrolet?

When OBDII code P0490 is triggered in a Chevrolet, common symptoms may include rough idling, reduced engine performance, and an illuminated Check Engine light.

2. What does the OBDII code P0490 Chevrolet indicate?

The OBDII code P0490 in a Chevrolet indicates a problem with the Exhaust Gas Recirculation (EGR) motor control circuit having high voltage.

3. What are the possible causes of OBDII code P0490 in a Chevrolet?

Possible causes of OBDII code P0490 in a Chevrolet include a faulty EGR valve, damaged wiring or connectors in the EGR system, or a malfunctioning EGR control module.

4. How can I diagnose the cause of OBDII code P0490 in my Chevrolet?

Diagnosing the cause of OBDII code P0490 in a Chevrolet involves checking the EGR valve for proper operation, inspecting the wiring and connectors for any damage, and testing the EGR control module using a multimeter.

5. Can I continue driving my Chevrolet with OBDII code P0490?

It is not recommended to continue driving your Chevrolet with OBDII code P0490 as it can lead to further damage to the engine and emissions systems. It is best to address the issue promptly.

6. How can I repair OBDII code P0490 in my Chevrolet?

Repairing OBDII code P0490 in a Chevrolet may involve replacing the faulty EGR valve, repairing damaged wiring or connectors, or replacing the EGR control module as necessary.

7. Are there any DIY tips for fixing OBDII code P0490 in a Chevrolet?

While some basic troubleshooting steps can be done by DIY enthusiasts, diagnosing and repairing OBDII code P0490 may require advanced tools and knowledge. It is recommended to consult a professional mechanic for proper diagnosis and repair.

8. Will OBDII code P0490 Chevrolet cause a vehicle to fail emissions testing?

Yes, OBDII code P0490 in a Chevrolet can cause the vehicle to fail emissions testing due to its impact on the EGR system, which plays a significant role in reducing emissions.

9. How much does it typically cost to repair OBDII code P0490 in a Chevrolet?

The cost to repair OBDII code P0490 in a Chevrolet can vary depending on the specific cause of the issue, parts needed for replacement, and labor costs. It is advisable to obtain a few quotes from different mechanics for an accurate estimate.

10. Can resetting the Check Engine light resolve OBDII code P0490 in a Chevrolet?

Resetting the Check Engine light may temporarily turn off the warning indicator, but it will not fix the underlying issue causing OBDII code P0490 in a Chevrolet. It is crucial to address the root cause of the problem to prevent further issues.