AutoCodes – Mercury – P140A Mercury

P140A Mercury Code - Exhaust Gas Recirculation Sensor 'C' Circuit Low

Quick Answer

The Powertrain Control Module (PCM) monitors the Exhaust Gas Recirculation (EGR) Sensor. Common causes include Faulty Exhaust Gas Recirculation (EGR) Sensor, Exhaust Gas Recirculation (EGR) Sensor harness is open or shorted, Exhaust Gas Recirculation (EGR) Sensor 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: P140A Mercury indicates Exhaust Gas Recirculation Sensor 'C' Circuit Low.
Common causes: Common causes include Faulty Exhaust Gas Recirculation (EGR) Sensor, Exhaust Gas Recirculation (EGR) Sensor harness is open or shorted, Exhaust Gas Recirculation (EGR) Sensor 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 1,647

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 Sep 24, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P140A Mercury Description

The Powertrain Control Module (PCM) monitors the Exhaust Gas Recirculation (EGR) Sensor. The PCM sets the OBDII code when the Exhaust Gas Recirculation Sensor is not to factory specifications.

OBDII Code P140A Mercury - Exhaust Gas Recirculation Sensor 'C' Circuit Low - AutoCodes.com — P140A Mercury Code - Exhaust Gas Recirculation Sensor 'C' Circuit Low

What does this mean?

What are the Possible Causes of the DTC P140A Mercury?

Faulty Exhaust Gas Recirculation (EGR) Sensor
Exhaust Gas Recirculation (EGR) Sensor harness is open or shorted
Exhaust Gas Recirculation (EGR) Sensor circuit poor electrical connection

How to Fix the DTC P140A Mercury?

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 P140A Mercury 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 P140A Mercury code?

Need more information on how to fix the P140A Mercury 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 P140A Mercury Code

1. What are the common symptoms of OBDII code P140A in a Mercury vehicle?

- Common symptoms include rough idling, engine hesitation, decreased fuel efficiency, and the illumination of the check engine light.

2. What does the OBDII code P140A for Exhaust Gas Recirculation Sensor 'C' Circuit Low mean in a Mercury?

- This code indicates a low voltage condition in the circuit related to the Exhaust Gas Recirculation (EGR) sensor 'C', which monitors the EGR system's operation.

3. What are the possible causes of the P140A code in a Mercury related to the EGR sensor 'C' circuit?

- The code can be triggered by issues such as a faulty EGR sensor, damaged wiring or connectors, a clogged EGR valve, or a malfunctioning EGR solenoid.

4. How can I diagnose the P140A code in my Mercury?

- Diagnosis typically involves using an OBDII scanner to retrieve the code, visually inspecting the EGR system components, testing the EGR sensor 'C' circuit for continuity and voltage, and checking for any related trouble codes.

5. Can I continue driving my Mercury with the P140A code present?

- While the vehicle may still be operable with the code, it is not recommended to ignore it, as it can lead to reduced engine performance and potential long-term damage to the EGR system.

6. How can I repair the P140A code in my Mercury?

- Repair steps may include replacing the EGR sensor 'C', repairing or replacing damaged wiring or connectors, cleaning or replacing the EGR valve, and ensuring proper operation of the EGR system components.

7. Is it possible to clear the P140A code in my Mercury without fixing the underlying issue?

- Clearing the code without addressing the root cause may temporarily turn off the check engine light, but the issue will likely reappear once the ECU detects the problem during subsequent driving cycles.

8. Can a DIY enthusiast tackle the repair for the P140A code, or is professional assistance recommended?

- Depending on your skill level and access to tools, DIY repair of the P140A code may be possible for simple tasks like replacing the EGR sensor 'C'. However, more complex diagnostics and repairs may require professional assistance.

9. How long does it typically take to repair the P140A code in a Mercury?

- The repair time can vary depending on the exact cause of the code and the complexity of the repair needed. Simple fixes like replacing a sensor may take an hour or two, while more involved repairs could take longer.

10. Are there any preventive maintenance tips to avoid the recurrence of the P140A code in my Mercury?

- Regularly servicing the EGR system, using high-quality fuel, and addressing any engine performance issues promptly can help prevent the reoccurrence of the P140A code in your Mercury.