AutoCodes – GMC – P0405 2016 GMC Sierra

P0405 2016 GMC Sierra Code - Exhaust Gas Recirculation Position Sensor Circuit Low Voltage

Quick Answer

The Engine Control Module (ECM) uses the Exhaust Gas Recirculation (EGR) position sensor to determine the position of the EGR valve. 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 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: P0405 2016 GMC Sierra indicates Exhaust Gas Recirculation Position Sensor Circuit Low 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: 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 255

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 20, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0405 2016 GMC Sierra Description

The Engine Control Module (ECM) uses the Exhaust Gas Recirculation (EGR) position sensor to determine the position of the EGR valve. The ECM sends a reference voltage through the 5 V reference circuit to the EGR position sensor. The ECM provides a voltage return path for the sensor through the low reference circuit. A variable voltage signal, based on the EGR valve position, is sent from the sensor to the ECM through the EGR position sensor signal circuit. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the EGR position sensor voltage is less than 0.25 V for greater than 5 s.

OBDII Code P0405 2016 GMC Sierra - Exhaust Gas Recirculation Position Sensor Circuit Low Voltage - AutoCodes.com — P0405 2016 GMC Sierra Code - Exhaust Gas Recirculation Position Sensor Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0405 2016 GMC Sierra?

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 P0405 2016 GMC Sierra?

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 P0405 2016 GMC Sierra 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 P0405 2016 GMC Sierra code?

Need more information on how to fix the P0405 2016 GMC Sierra 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 P0405 2016 GMC Sierra Code

1. What does the OBDII code P0405 mean for a 2016 GMC Sierra?

P0405 indicates that the Exhaust Gas Recirculation (EGR) Position Sensor Circuit is reading a voltage lower than the expected range.

2. What are the common symptoms of code P0405 in a 2016 GMC Sierra?

Symptoms may include a check engine light, reduced engine performance, rough idling, increased fuel consumption, or engine hesitation during acceleration.

3. What causes the P0405 code to appear in my GMC Sierra?

Possible causes include a faulty EGR position sensor, damaged wiring or connectors in the EGR circuit, carbon buildup in the EGR valve, or a malfunctioning EGR valve.

4. Can I still drive my 2016 GMC Sierra with a P0405 code?

While the vehicle may still be drivable, ignoring the code can lead to reduced performance, increased emissions, and potential damage to the engine or catalytic converter over time.

5. How do I diagnose the P0405 code on my GMC Sierra?

Diagnosis involves checking the EGR position sensor with a multimeter, inspecting the wiring and connectors for damage, and testing the EGR valve for proper operation.

6. Is the P0405 code related to carbon buildup in the EGR system?

Yes, excessive carbon buildup can restrict the EGR valve's movement, leading to incorrect position sensor readings and triggering the P0405 code.

7. How can I fix the P0405 code on my 2016 GMC Sierra?

Repairs may include cleaning or replacing the EGR valve, replacing the EGR position sensor, repairing damaged wiring, or clearing carbon buildup in the intake system.

8. How much does it cost to repair the P0405 code on a GMC Sierra?

Costs vary, but replacing the EGR position sensor typically ranges from $150 to $400, including parts and labor. Cleaning the EGR valve may be less expensive.

9. Can a faulty EGR position sensor cause long-term damage to my GMC Sierra?

Yes, a faulty sensor can lead to improper EGR operation, increased emissions, and potential engine or catalytic converter damage over time.

10. Will clearing the P0405 code with a scanner fix the issue permanently?

No, clearing the code without addressing the underlying problem will only reset the check engine light temporarily. The code will return if the issue persists.