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Engine-Codes – Chevrolet – P0402 2017 Chevrolet Silverado

P0402 2017 Chevrolet Silverado Code - Exhaust Gas Recirculation Flow Excessive

Quick Answer

The P0402 diagnostic trouble code (DTC) for a 2017 Chevrolet Silverado indicates that there is excessive exhaust gas recirculation (EGR) flow detected by the vehicle's engine control module (ECM). Common causes include Malfunctioning EGR Valve: A faulty EGR valve that is stuck open or closed can cause excessive EGR flow, Clogged EGR Passage: Accumulated carbon deposits or debris in the EGR passage can obstruct the flow of exhaust gases, Faulty EGR Temperature Sensor: A malfunctioning EGR temperature sensor may provide incorrect readings to the ECM, leading to excessive EGR flow. 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 Malfunctioning EGR Valve: A faulty EGR valve that is stuck open or closed can cause excessive EGR flow, Clogged EGR Passage: Accumulated carbon deposits or debris in the EGR passage can obstruct the flow of exhaust gases, Faulty EGR Temperature Sensor: A malfunctioning EGR temperature sensor may provide incorrect readings to the ECM, leading to excessive EGR flow.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 17, 2024
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Code P0402 2017 Chevrolet Silverado Description

The P0402 diagnostic trouble code (DTC) for a 2017 Chevrolet Silverado indicates that there is excessive exhaust gas recirculation (EGR) flow detected by the vehicle's engine control module (ECM). The EGR system is responsible for recirculating a portion of the exhaust gases back into the intake manifold to reduce nitrogen oxide emissions and control combustion temperatures. When the ECM detects that the EGR flow is higher than expected, it triggers the P0402 code.

OBDII Code P0402 2017 Chevrolet Silverado - Exhaust Gas Recirculation Flow Excessive
P0402 2017 Chevrolet Silverado Code - Exhaust Gas Recirculation Flow Excessive

Common Causes of P0402 2017 Chevrolet Silverado

  1. Malfunctioning EGR Valve: A faulty EGR valve that is stuck open or closed can cause excessive EGR flow.
  2. Clogged EGR Passage: Accumulated carbon deposits or debris in the EGR passage can obstruct the flow of exhaust gases.
  3. Faulty EGR Temperature Sensor: A malfunctioning EGR temperature sensor may provide incorrect readings to the ECM, leading to excessive EGR flow.
  4. EGR Solenoid Issues: Problems with the EGR solenoid, such as a wiring issue or a faulty solenoid, can disrupt the EGR flow.
  5. Vacuum Leaks: Any vacuum leaks in the EGR system can also contribute to excessive EGR flow.

Symptoms of P0402 2017 Chevrolet Silverado

  1. Check Engine Light: The most common symptom associated with the P0402 code is the illumination of the check engine light on the vehicle's dashboard.
  2. Reduced Engine Performance: Excessive EGR flow can lead to a decrease in engine performance, including reduced power and acceleration.
  3. Rough Idling: The engine may experience rough idling or stalling when the EGR system is not functioning correctly.
  4. Increased Emissions: The vehicle may fail emissions tests due to the higher levels of nitrogen oxides being emitted.
  5. Poor Fuel Efficiency: Excessive EGR flow can also result in poor fuel efficiency, causing the vehicle to consume more fuel than usual.

How to Fix P0402 2017 Chevrolet Silverado

  1. Diagnose the Issue: Use a scan tool to retrieve the DTC and perform a visual inspection of the EGR system components to identify the root cause of the problem.
  2. Clean or Replace EGR Valve: Clean the EGR valve to remove any carbon buildup or replace it if it is faulty.
  3. Clear EGR Passage: Remove any obstructions in the EGR passage to ensure proper flow of exhaust gases.
  4. Test EGR Temperature Sensor: Check the EGR temperature sensor for proper operation and replace it if necessary.
  5. Inspect EGR Solenoid: Test the EGR solenoid for functionality and replace it if it is not working correctly.

Cost to Fix P0402 2017 Chevrolet Silverado

The typical repair costs for addressing the P0402 code on a 2017 Chevrolet Silverado can range from $200 to $500, including parts and labor. However, the specific diagnosis time and labor rates at auto repair shops can vary based on factors such as location, vehicle make and model, and engine type. Most auto repair shops charge between $80 and $150 per hour for labor, but rates may be higher in metropolitan areas or at dealerships, while independent shops often charge less. It is recommended to check local rates for a more accurate estimate before proceeding with the repair.

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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.

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