AutoCodes – Chevrolet – P040B 2018 Chevrolet Silverado

P040B 2018 Chevrolet Silverado Code - Exhaust Gas Recirculation Temperature Sensor 2 Performance

Quick Answer

The Exhaust Gas Recirculation (EGR) temperature sensors are variable resistors that measure the temperature of the exhaust gas at the inlet and outlet of the EGR cooler. Common causes include Faulty Exhaust Gas Recirculation (EGR) Temperature Sensor 2, Exhaust Gas Recirculation Temperature Sensor 2 harness is open or shorted, Exhaust Gas Recirculation Temperature Sensor 2 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: P040B 2018 Chevrolet Silverado indicates Exhaust Gas Recirculation Temperature Sensor 2 Performance.
Common causes: Common causes include Faulty Exhaust Gas Recirculation (EGR) Temperature Sensor 2, Exhaust Gas Recirculation Temperature Sensor 2 harness is open or shorted, Exhaust Gas Recirculation Temperature Sensor 2 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 319

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 Jun 20, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P040B 2018 Chevrolet Silverado Description

The Exhaust Gas Recirculation (EGR) temperature sensors are variable resistors that measure the temperature of the exhaust gas at the inlet and outlet of the EGR cooler. The Engine Control Module (ECM) supplies 5 volts to the EGR temperature sensor signal circuit and a ground for the low reference circuit. When the EGR temperature sensor is cold, the sensor resistance is high. When the EGR temperature increases, the sensor resistance decreases. The ECM detects a higher voltage on the EGR temperature signal circuit with high sensor resistance. With lower sensor resistance, the ECM detects a lower voltage on the EGR temperature signal circuit. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the EGR temperature sensor has not changed greater than a calibrated amount for greater than a calibrated amount of time following a cold start.

OBDII Code P040B 2018 Chevrolet Silverado - Exhaust Gas Recirculation Temperature Sensor 2 Performance - AutoCodes.com — P040B 2018 Chevrolet Silverado Code - Exhaust Gas Recirculation Temperature Sensor 2 Performance

What does this mean?

What are the Possible Causes of the DTC P040B 2018 Chevrolet Silverado?

Faulty Exhaust Gas Recirculation (EGR) Temperature Sensor 2
Exhaust Gas Recirculation Temperature Sensor 2 harness is open or shorted
Exhaust Gas Recirculation Temperature Sensor 2 circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P040B 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 P040B 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 P040B 2018 Chevrolet Silverado code?

Need more information on how to fix the P040B 2018 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 P040B 2018 Chevrolet Silverado Code

1. What does the OBDII code P040B mean on a 2018 Chevrolet Silverado?

P040B indicates an issue with the Exhaust Gas Recirculation (EGR) Temperature Sensor 2, specifically a performance problem or abnormal readings.

2. What are the common symptoms of the P040B code on a Chevy Silverado?

Symptoms may include the Check Engine Light turning on, reduced fuel efficiency, rough idling, poor engine performance, and possible engine hesitation.

3. What causes the P040B code to appear?

Common causes include a faulty EGR temperature sensor, wiring or connector issues, excessive carbon buildup in the EGR system, or a failed EGR valve.

4. Can I drive my 2018 Silverado with a P040B code?

While the vehicle may remain drivable, ignoring the code can lead to reduced performance, increased emissions, and potential damage to the EGR system over time.

5. How do I diagnose the P040B code on my Silverado?

Start by using an OBDII scanner to confirm the code, inspect the EGR temperature sensor and its wiring for damage, and check for carbon buildup in the EGR passages.

6. How do I fix the P040B code on a 2018 Chevy Silverado?

Repairs may include replacing the faulty EGR temperature sensor, cleaning the EGR system to remove carbon deposits, repairing damaged wiring, or replacing the EGR valve if necessary.

7. How much does it cost to fix the P040B code?

Repair costs vary, but replacing the EGR temperature sensor typically ranges from $150 to $300, including parts and labor, depending on your location and mechanic.

8. Can a dirty EGR system cause the P040B code?

Yes, excessive carbon buildup in the EGR system can interfere with sensor readings and cause the P040B code to trigger.

9. Is the P040B code related to emissions?

Yes, the EGR system plays a key role in reducing emissions, so a P040B code may indicate your vehicle is emitting higher levels of pollutants.

10. Do I need a professional mechanic to fix the P040B code?

While experienced DIYers may be able to address the issue, diagnosing and repairing the EGR system often requires specialized tools and knowledge, so a professional mechanic is recommended.