P046E Exhaust Gas Recirculation Sensor “B” Circuit Range/Performance

Home » OBD Codes » P0400-P0499 » P046E Exhaust Gas Recirculation Sensor “B” Circuit Range/Performance

P046E Exhaust Gas Recirculation Sensor “B” Circuit Range/Performance

OBD-II Trouble Code Technical Description

Exhaust Gas Recirculation Sensor "B" Circuit Range/Performance

What does that mean?

This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. However, specific troubleshooting steps will vary depending on the vehicle.

On board diagnostics (OBD) trouble code P046E is a generic trouble code relating to a range or performance problem incurred in the "B" electrical circuit to the exhaust gas recirculation (EGR) valve.

The purpose of the EGR valve is to introduce a regulated amount of exhaust gas into the intake manifold. The purpose is to maintain cylinder head temperatures below 2500-degrees F. Nitrates of Oxygen (Nox) form when temperatures rise above 2500-degrees F. Nox is responsible for smog and atmospheric pollution.

The controlling computer, either the powertrain control module (PCM) or the electronic control module (ECM) has detected an abnormally low, high or non-existent signal voltage. Refer to a manufacturer specific repair guide to determine which is the "B" sensor in your exact vehicle.

EGR Operating Principals

The trouble code P046E refers to the same problem on all vehicles, however, there are many types of EGRs, sensors and methods of activation. The only similarity is that they all vent exhaust gas into the intake manifold to cool the cylinder head temperatures.

Introducing spent exhaust gas into the engine at the wrong time reduces horsepower and causes a rough idle or stall. With this in mind, computer programming only opens the EGR when the engine RPM is above 2000 and to close when under a load.

Symptoms

The symptoms depend on the position of the EGR pintle at the time of failure.

  • The service engine soon light will illuminate and the OBD code P046E will be set. Additionally, a second code relating to the EGR sensor failure may be set. Code P044C relates to a low sensor voltage and P044D relates to a high voltage situation
  • If the EGR pintle is stuck partly open, the vehicle will not idle well or stalls
  • Ping from detonation may be heard when under a load or at high RPM
  • No symptoms at all
  • Potential Causes

  • Defective EGR sensor "B"
  • Defect in the wiring harness to the sensor
  • EGR pintle stuck in the closed position and a build up of carbon is preventing it from opening
  • Lack of vacuum to the EGR solenoid
  • Defective EGR solenoid
  • Defective EGR position sensor
  • Defective differential pressure feedback EGR sensor.
  • Repair Procedures

    All EGR valves have one thing in common-they re-circulate exhaust from the exhaust to the intake manifold. Other than that, they differ in their methods for regulating the opening of the pintle and sensing its position.

    The following repair procedures represent the most common problems accounting for the majority of failures in the EGR system. Wiring harness or sensor failures require a service manual to determine the proper wire identification and diagnostic procedures.

    Keep in mind that the wiring differs between manufacturers and computers do not react well if the wrong wire is probed. If you probe the wrong wire and send excessive voltage through the computer’s sensor input terminal and the computer will fry.

    At the same time, if the wrong connector is disconnected the computer could lose its programming causing the vehicle to fail to start again until the dealer reprograms the computer.

  • The code P046E indicates a "B" circuit malfunction, so check the EGR sensor connector for corrosion, bent or pushed out terminals or loose connection. Clean off any corrosion and re-seat the connector.
  • Remove the electrical connector and remove the EGR. Check for coking in the EGRs intake and exhaust. Clean out any coking as necessary so the pintle will move up and down smoothly.
  • Check the vacuum line from the EGR to the solenoid and replace it if any defects are found.
  • Check the solenoid electrical connector for corrosion or defects.
  • If the vehicle is a Ford, follow the two vacuum hoses from the EGR to the differential pressure feedback EGR sensor (DPFE) in the rear of the manifold.
  • Check the two pressure hoses for corrosion. Experience dictates these hoses plug with carbon from the exhaust. Use a small pocket screwdriver or equivalent and clean the hoses of corrosion and the sensor will begin to operate again.
  • If the most common tests failed to solve the problem, a service manual is needed to continue to test the wiring circuits. The best solution is to take the vehicle to a service facility with the proper diagnostic equipment. They can quickly identify and repair this type of problem.

    Need help?

    Let us fix your problem. You are most welcome our diagnosis experts have in most cases the knowledge and skills to find the cause of the error code p046e and to solve the problems.

    Make an appointment for diagnosis

    "Delete Error Code Permanently, Disable DTC Error Code Function for p046e in the ECU"

    In extreme cases, we even have the option to permanently remove the specific DTC p046e and disable the function of the specific error code in the ECU. All other fault code functions will then continue to work to protect the engine. This is different from clearing an error code with a diagnostic device. We have the option to permanently remove the function of the specific error code, so that it never comes back. Also emergency running that occurs on the specific error code can be solved in most cases.

    Of course we prefer to first try to solve the cause of the error code, but sometimes the only solution is to permanently disable the DTC function of p046e.

    Make an appointment for permanent removal of p046e