Technical Description of OBD-II Trouble Code
Range/Performance Issue in the Circuit of Exhaust Gas Recirculation Sensor “B”
What does that signify?
This is a generic diagnostic trouble code (DTC) for powertrain, which applies to all makes and models from 1996 onwards. However, the specific troubleshooting steps may vary depending on the vehicle.
OBD trouble code P046E indicates a range or performance problem in the electrical circuit “B” of the exhaust gas recirculation (EGR) valve. The EGR valve is responsible for introducing a regulated amount of exhaust gas into the intake manifold to maintain cylinder head temperatures below 2500-degrees F and prevent the formation of Nitrates of Oxygen (Nox) that contribute to 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. To identify the “B” sensor in your specific vehicle, refer to the manufacturer’s repair guide.
EGR Operating Principles
The trouble code P046E refers to the same problem in all vehicles, but there are various types of EGRs, sensors, and activation methods. The common factor is that they all release exhaust gas into the intake manifold to cool the cylinder head temperatures.
Introducing spent exhaust gas into the engine at the wrong time can reduce horsepower, cause a rough idle, or result in stalling. Therefore, the computer programming only opens the EGR when the engine RPM is above 2000 and closes it when under a load.
Symptoms
The symptoms depend on the position of the EGR pintle at the time of failure.
Potential Causes
Repair Procedures
All EGR valves have one common function, which is to recirculate exhaust from the exhaust to the intake manifold. However, they differ in terms of how they regulate the opening of the pintle and sense its position.
The following repair procedures address the most common problems that account for the majority of failures in the EGR system. For wiring harness or sensor failures, refer to a service manual for proper wire identification and diagnostic procedures.
It is important to note that wiring differs between manufacturers, and probing the wrong wire can cause damage to the computer. Similarly, disconnecting the wrong connector can result in the loss of computer programming, requiring reprogramming by a dealer to start the vehicle again.
If the common tests fail to resolve the issue, consult a service manual for further testing of the wiring circuits. The best solution is to take the vehicle to a service facility equipped with the necessary diagnostic equipment to quickly identify and repair the problem.
