AutoCodes – Chevrolet – P0402 2018 Chevrolet Silverado

P0402 2018 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 2018 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 298

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 2018 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 2018 Chevrolet Silverado - Exhaust Gas Recirculation Flow Excessive - AutoCodes.com — P0402 2018 Chevrolet Silverado Code - Exhaust Gas Recirculation Flow Excessive

What does this mean?

What are the Possible Causes of the DTC P0402 2018 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 2018 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 2018 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 2018 Chevrolet Silverado code?

Need more information on how to fix the P0402 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

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Get the P0402 2018 Chevrolet Silverado code diagnosed by a professional: Find a repair shop in your area

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 2018 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P0402 in a 2018 Chevrolet Silverado?

The common symptoms of code P0402 in a 2018 Chevrolet Silverado include a rough idle, decreased fuel efficiency, and potentially an illuminated check engine light.

2. What does the OBDII code P0402 indicate on a 2018 Chevrolet Silverado?

Code P0402 on a 2018 Chevrolet Silverado indicates that there is excessive flow detected in the Exhaust Gas Recirculation (EGR) system.

3. What are the possible causes of OBDII code P0402 in a 2018 Chevrolet Silverado?

Possible causes of code P0402 in a 2018 Chevrolet Silverado include a faulty EGR valve, clogged EGR passages, a malfunctioning EGR temperature sensor, or a problem with the EGR solenoid.

4. How can I diagnose the OBDII code P0402 in my 2018 Chevrolet Silverado?

To diagnose code P0402 in a 2018 Chevrolet Silverado, you can start by checking the EGR valve for proper operation, inspecting the EGR passages for blockages, and testing the EGR temperature sensor and solenoid.

5. Can I continue driving my 2018 Chevrolet Silverado with OBDII code P0402?

It is not recommended to continue driving your 2018 Chevrolet Silverado with code P0402 as it can lead to reduced engine performance and potential damage over time. It is best to address the issue promptly.

6. How serious is OBDII code P0402 on a 2018 Chevrolet Silverado?

While code P0402 may not cause immediate engine failure, it can impact the performance and emissions of your 2018 Chevrolet Silverado. Ignoring the issue can result in further damage to components.

7. Are there any simple repairs I can try for OBDII code P0402 on my 2018 Chevrolet Silverado?

Simple repairs for code P0402 in a 2018 Chevrolet Silverado may include cleaning the EGR valve, checking and clearing any blockages in the EGR passages, or replacing a faulty EGR temperature sensor.

8. How much does it typically cost to repair OBDII code P0402 in a 2018 Chevrolet Silverado?

The cost to repair code P0402 in a 2018 Chevrolet Silverado can vary depending on the exact cause of the issue, but it may range from $200 to $500 or more, including parts and labor.

9. Can a DIY enthusiast fix OBDII code P0402 in a 2018 Chevrolet Silverado?

Depending on your mechanical skills and access to tools, a knowledgeable DIY enthusiast may be able to address code P0402 in a 2018 Chevrolet Silverado by following repair guides and utilizing the necessary resources.

10. How long does it typically take to repair OBDII code P0402 in a 2018 Chevrolet Silverado?

The time to repair code P0402 in a 2018 Chevrolet Silverado can vary based on the specific issue, but a professional mechanic may take anywhere from 1 to 3 hours to diagnose and fix the problem.