P0406 Mercury Code - Exhaust Gas Recirculation Sensor 'A' Circuit High
Quick Answer
Early Exhaust Gas Recirculation (EGR) systems component s include and EGR Valve, and Engine Control Μodule (ECΜ) Controlled Vacuum Switch Valve or EGR Solenoid and an EGR Vacuum Μodulator. Common causes include Faulty EGR volume control solenoid valve, Carbon built up on EGR valve, EGR volume control solenoid valve harness is open or shorted. 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
- P0406 Mercury indicates Exhaust Gas Recirculation Sensor 'A' Circuit High.
- Common causes
- Common causes include Faulty EGR volume control solenoid valve, Carbon built up on EGR valve, EGR volume control solenoid valve harness is open or shorted.
- 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.
Code P0406 Mercury Description
The EGR system on recently built vehicles uses a step motor to control the flow rate of EGR from exhaust manifold. This motor has four winding phases. It operates according to the output pulse signal of the ECΜ. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECΜ does not issue the pulse signal. Α certain voltage signal is issued so that the valve remains at that particular opening.
What are the Possible Causes of the DTC P0406 Mercury?
- Faulty EGR volume control solenoid valve
- Carbon built up on EGR valve
- EGR volume control solenoid valve harness is open or shorted
- EGR volume control solenoid valve circuit poor electrical connection
- Faulty EGR temperature sensor and circuit
How to Fix the DTC P0406 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 P0406 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.
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Frequently Asked Questions about P0406 Mercury Code
1. What are common symptoms of OBDII code P0406 in a Mercury vehicle?
- Common symptoms include rough idling, decreased fuel efficiency, engine stalling, and the illumination of the Check Engine light.
2. What does the OBDII code P0406 in a Mercury indicate about the Exhaust Gas Recirculation (EGR) system?
- The code indicates a high voltage condition in the circuit for the EGR sensor 'A', which monitors the operation of the EGR system.
3. What are potential causes of OBDII code P0406 in a Mercury?
- Potential causes include a faulty EGR sensor 'A', damaged wiring or connectors in the EGR circuit, a clogged EGR valve, or issues with the EGR system's operation.
4. How can I diagnose the OBDII code P0406 in my Mercury?
- Diagnosing the code typically involves checking the EGR sensor 'A' for proper voltage readings, inspecting the EGR valve for blockages, and testing the wiring and connectors for any faults.
5. Can I continue driving my Mercury with OBDII code P0406 present?
- It is not recommended to continue driving with the code present, as it can lead to further damage to the engine and emissions system if left unresolved.
6. How can I repair OBDII code P0406 in my Mercury?
- Repair options may include replacing the EGR sensor 'A', cleaning or replacing the EGR valve, repairing damaged wiring or connectors, or addressing any underlying issues with the EGR system.
7. Will resetting the Check Engine light resolve OBDII code P0406 in my Mercury?
- Resetting the light may temporarily clear the code, but it will likely return if the underlying issue with the EGR sensor 'A' circuit high is not addressed.
8. Are there any preventative maintenance tips to avoid OBDII code P0406 in a Mercury?
- Regularly servicing and cleaning the EGR system, using high-quality fuel, and following the manufacturer's maintenance schedule can help prevent issues that lead to code P0406.
9. How long does it typically take to repair OBDII code P0406 in a Mercury?
- The repair time can vary depending on the specific cause of the code, but it may take anywhere from an hour to several hours to diagnose and fix the issue.
10. Can a DIY enthusiast fix OBDII code P0406 in a Mercury, or is professional help necessary?
- While some aspects of diagnosing and repairing the code can be done by a DIY enthusiast with the right tools and knowledge, professional help may be necessary for more complex issues or if unsure about the repair process.
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