Diagnostic Trouble Code (DTC) P0471 refers to "Exhaust Pressure Sensor Range/Performance." This code is set when the powertrain control module (PCM) detects that the signal from the exhaust pressure sensor is outside of the expected range, or when the sensor fails to provide a signal to the PCM.
The exhaust pressure sensor is responsible for measuring the pressure in the exhaust system, which helps the PCM control the amount of exhaust gas recirculation (EGR) and manage the diesel particulate filter (DPF).
When the P0471 code is set, it may indicate a problem with the exhaust pressure sensor itself, or with the wiring or connections to the sensor. It could also indicate an issue with the exhaust system, such as a clogged or damaged exhaust pipe.
To diagnose and fix the problem, a technician would typically start by checking the wiring and connections to the exhaust pressure sensor to ensure that they are intact and properly connected. They would also check the exhaust system for damage or blockages, and replace the sensor if necessary. The exact steps and procedures for diagnosis and repair will depend on the specific make and model of the vehicle.
