AutoCodes – Generic – P140C

P140C Code - Exhaust Gas Recirculation Slow Response Decreasing Flow

Quick Answer

The Exhaust Gas Recirculation (EGR) valve is an electrically controlled valve that is controlled by the Engine Control Module (ECM). 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 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: P140C indicates Exhaust Gas Recirculation Slow Response Decreasing Flow.
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: 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 20,171

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 Jul 25, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P140C Description

The Exhaust Gas Recirculation (EGR) valve is an electrically controlled valve that is controlled by the Engine Control Module (ECM). The EGR allows a specific amount of your exhaust gas into the intake manifold. This exhaust gas mixes with the intake air and cools the combustion process. The recirculated exhaust gas also prevents the formation of nitrogen oxides (NOx). The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the actual EGR flow is lower than a calibrated value for greater than 5 s.

OBDII Code P140C - Exhaust Gas Recirculation Slow Response Decreasing Flow - AutoCodes.com — P140C Code - Exhaust Gas Recirculation Slow Response Decreasing Flow

What does this mean?

What are the Possible Causes of the DTC P140C?

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 P140C?

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 P140C 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 P140C code?

Need more information on how to fix the P140C code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P140C code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P140C Buick — Exhaust Gas Recirculation Slow Response Decreasing Flow
P140C Cadillac — Exhaust Gas Recirculation Slow Response Decreasing Flow
P140C Chevrolet — Exhaust Gas Recirculation Slow Response Decreasing Flow
P140C Ford — Exhaust Gas Recirculation Control Circuit 'B'
P140C GMC — Exhaust Gas Recirculation Slow Response Decreasing Flow
P140C Lincoln — Exhaust Gas Recirculation Control Circuit 'B'
P140C Mercury — Exhaust Gas Recirculation Control Circuit 'B'

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 P140C Code

1. What are the common symptoms of OBDII code P140C (Exhaust Gas Recirculation Slow Response Decreasing Flow)?

The common symptoms include rough idling, decreased engine performance, and the illumination of the Check Engine Light.

2. What are the potential causes of OBDII code P140C?

Possible causes of this code include a faulty EGR valve, carbon buildup in the EGR system, wiring issues, or a malfunctioning EGR temperature sensor.

3. How can I diagnose the cause of OBDII code P140C?

To diagnose the issue, you can perform a visual inspection of the EGR system, test the EGR valve for proper operation, check the wiring for any damage, and use a scan tool to monitor EGR system data.

4. Can I continue driving my vehicle with OBDII code P140C?

It is not recommended to continue driving with this code as it can lead to decreased fuel efficiency and potential damage to the engine over time. It is best to address the issue promptly.

5. How can I repair OBDII code P140C?

Repair options include cleaning or replacing the EGR valve, cleaning carbon deposits from the EGR system, repairing any damaged wiring, or replacing the EGR temperature sensor if necessary.

6. Is it possible to prevent OBDII code P140C from occurring in the future?

Regular maintenance, such as cleaning the EGR system components and ensuring proper engine operation, can help prevent the recurrence of this code.

7. Can a DIY enthusiast fix OBDII code P140C at home?

Depending on your skill level and access to tools, some individuals may be able to address this code at home by following repair guides or tutorials. However, professional assistance may be needed for more complex issues.

8. How much does it typically cost to repair OBDII code P140C?

The cost of repairs can vary depending on the underlying cause of the code and labor rates in your area. It is recommended to obtain quotes from local mechanics or repair shops for an accurate estimate.

9. Will resetting the Check Engine Light resolve OBDII code P140C?

Simply resetting the Check Engine Light will not fix the underlying issue causing the code. It is important to diagnose and repair the root cause to prevent the code from returning.

10. Is OBDII code P140C a serious issue that requires immediate attention?

While it may not cause immediate harm to your vehicle, addressing this code promptly is important to prevent potential engine damage and maintain optimal performance.