AutoCodes – Chevrolet – P0402 2017 Chevrolet Silverado

P0402 2017 Chevrolet Silverado Code - Exhaust Gas Recirculation Flow Excessive

Quick Answer

The Exhaust Gas Recirculation (EGR) valve is controlled by the Engine Control Module (ECM). Common causes include Faulty Exhaust Gas Recirculation (EGR) Valve, EGR solenoid valve harness is open or shorted, EGR solenoid valve circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P0402 2017 Chevrolet Silverado indicates Exhaust Gas Recirculation Flow Excessive.
Common causes: Common causes include Faulty Exhaust Gas Recirculation (EGR) Valve, EGR solenoid valve harness is open or shorted, EGR solenoid valve circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 367

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 19, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0402 2017 Chevrolet Silverado Description

The Exhaust Gas Recirculation (EGR) valve is controlled by the Engine Control Module (ECM). The ECM controls the EGR valve by supplying a 12-volt pulse width modulated signal to the EGR Valve low control circuit and 12 volts to the high control circuit. The ECM monitors the EGR flow performance when the EGR is active by comparing the desired Mass Air Flow (MAF) to the actual MAF. If the difference between the desired MAF and the actual MAF is less than or greater than a calibrated threshold level the amount of detected EGR flow is out of range. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the difference between the desired mass air flow and the actual mass air flow is less than a calibrated value for greater than 12.5 s.

OBDII Code P0402 2017 Chevrolet Silverado - Exhaust Gas Recirculation Flow Excessive - AutoCodes.com — P0402 2017 Chevrolet Silverado Code - Exhaust Gas Recirculation Flow Excessive

What does this mean?

What are the Possible Causes of the DTC P0402 2017 Chevrolet Silverado?

Faulty Exhaust Gas Recirculation (EGR) Valve
EGR solenoid valve harness is open or shorted
EGR solenoid valve circuit poor electrical connection

How to Fix the DTC P0402 2017 Chevrolet Silverado?

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 P0402 2017 Chevrolet Silverado 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 P0402 2017 Chevrolet Silverado code?

Need more information on how to fix the P0402 2017 Chevrolet Silverado code? Get Access to Factory Service Manuals

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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 P0402 2017 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P0402 in a 2017 Chevrolet Silverado?

The common symptoms of code P0402 on a 2017 Chevrolet Silverado include reduced fuel efficiency, rough idling, and potentially an illuminated check engine light.

2. What does the OBDII code P0402 on a 2017 Chevrolet Silverado indicate?

Code P0402 indicates that there is excessive exhaust gas recirculation (EGR) flow detected by the vehicle's computer system in the 2017 Chevrolet Silverado.

3. What are the possible causes of OBDII code P0402 in a 2017 Chevrolet Silverado?

Possible causes of code P0402 in a 2017 Chevrolet Silverado include a faulty EGR valve, clogged EGR passages, a malfunctioning EGR sensor, or a vacuum leak in the EGR system.

4. How can I diagnose the cause of OBDII code P0402 in my 2017 Chevrolet Silverado?

Diagnosing the cause of code P0402 may involve visually inspecting the EGR valve and related components, checking for vacuum leaks, and using a scan tool to monitor EGR system data for abnormalities.

5. Can I continue to drive my 2017 Chevrolet Silverado with OBDII code P0402?

While it may be possible to drive the vehicle with code P0402, it is recommended to address the issue promptly to prevent potential damage to the engine and ensure optimal performance and fuel efficiency.

6. How can I repair OBDII code P0402 on a 2017 Chevrolet Silverado?

Repairing code P0402 may involve cleaning or replacing the EGR valve, clearing any obstructions in the EGR passages, testing and replacing the EGR sensor if necessary, and addressing any vacuum leaks in the system.

7. Is it necessary to reset the OBDII code P0402 after making repairs to a 2017 Chevrolet Silverado?

After repairing the underlying issue causing code P0402, it is recommended to clear the code using an OBDII scan tool to reset the check engine light and ensure proper functioning of the EGR system.

8. How much does it typically cost to repair OBDII code P0402 in a 2017 Chevrolet Silverado?

The cost of repairing code P0402 can vary depending on the exact cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.

9. Can a DIY enthusiast fix OBDII code P0402 in a 2017 Chevrolet Silverado?

Depending on their skill level and access to tools, a DIY enthusiast may be able to diagnose and repair code P0402 in a 2017 Chevrolet Silverado by following step-by-step guides and utilizing online resources.

10. How often does OBDII code P0402 occur in a 2017 Chevrolet Silverado?

Code P0402 can occur sporadically or more frequently depending on the condition of the EGR system and related components in the 2017 Chevrolet Silverado. Regular maintenance and inspection can help prevent its occurrence.