Dodge Charger P0406: EGR Sensor “A” → Circuit High


P0406 It is a generic OBDII diagnostic code. This is the signal from the EGR system. In this case, it means that the signal coming from the EGR system is higher than the specified range. Being a generic code, it has the same meaning for the Dodge Charger as any other vehicle.

P0118 Dodge Charger

The EGR system allows a certain amount of the Charger’s exhaust gases to re-enter the combustion chamber, which helps reduce emissions from your Charger’s exhaust. When the EGR system has a problem, usually the only thing you’ll notice is the check engine light.

P0406: EGR Sensor “A” → Circuit High

P0406 Symptoms: Dodge Charger

Since the EGR valve is part of the emissions system, there are not always symptoms associated with P0406 (other than the check engine light).

These are the most common symptoms of P0406 when present:

  • Motor overheating and/or overload
  • check engine light
  • Higher combustion temperature
  • Greater emissions production

P0406 Causes: Dodge Charger

Almost always, P0406 is going to be caused by wiring problems or a bad EGR valve. We’ll review both in more detail below.

Faulty EGR valve

If you have a good scan tool, you can use it to command the EGR valve to open. If the EGR valve refuses to open, it would be time to check the voltage of the wiring harness at the plug that goes to the EGR. If the tension is fine, then replacing the EGR valve may be a good idea. There is a lot about checking this wiring in the next section.

Carbon, scrap metal, and even ice can cause the EGR circuit to become stuck. The most common cause of P0406 is the EGR valve. But blindly replacing it without testing it can be a waste of money.

If it ends up being the EGR valve, they are quite affordable.

Wiring problems

A good place to start diagnosing P0406 on your Charger is going to be the wiring harness. Since the wiring harness to the EGR valve is next to the hot engine, it has a higher propensity to fail than other wires in the vehicle, so it is often the problem.

Find the wiring harness where the EGR valve begins. Does it have any visible signs of damage? If not, inspect the wiring harness for any damage. You will look for frayed cables. Look closely at any place where it may come into contact with the engine, frame, or anywhere where it makes a sharp turn.

To check the voltage in the harness, you will need a voltmeter. Check the voltage in the reference circuit. If it is at 5 volts, but the EGR valve does not open, that is a good indication that the EGR is bad.

If you get 12 volts or 0 volts, that would be an indication of a wiring problem. Here’s a good article on diagnosing your wiring problems from


Most of the time, when P0406 is thrown, the cause will be the EGR valve. However, it is a good idea to check it and the wiring before purchasing a new one.

If there is anything you want to add, leave a comment below. Good luck diagnosing your charger!


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