P0471 - EXHAUST PRESSURE SENSOR RANGE / PERFORMANCE

The fault code P0471 OBDII means that the input signal from the Exhaust Pressure Sensor does not match the pressure in the intake manifold. This problem can be caused by electrical circuit failures but also by mechanical problems. When such a problem is detected, the Check Engine light will illuminate.

The DTC code P0470 may also appear next to this code. The difference between the two codes is the time of the problem, as well as the type of electrical or mechanical problem with the circuit, sensor, or controller.

• MIL (Engine Malfunction) light on.
• Loss of power.
• Other codes related to the exhaust system have been established.

When the diagnostic code P0471 OBD2 is stored, it is because one or more of the following issues have occurred:

• In the pipe from the intake manifold to the Exhaust Pressure Sensor, there may be elements that block it.
• Air leaks in the EVAP system (Evaporative Emission Control System).
• The Exhaust Pressure Sensor may be defective.

These are the steps for troubleshooting DTC code P0471 OBDII:

• See the TSB (Technical Service Bulletins). The solution may be known by the manufacturer.
• Locate the Exhaust Pressure Sensor, then disconnect the pipe between the sensor and the intake manifold. Check for carbon build-up inside. If you see water coming out, that could have been the cause of the code.
• Check cables and connectors with burned spots or rubbing against other components. Also, inspect connector terminals for corrosion. Replace if there are problems with these components.
• Make sure that the tube connecting the turbocharger to the intake manifold does not leak. If you find poor connections, adjust them, and clear the code.
• If the code returns, test the sensor and associated circuits. Disconnect the wires leading to the Exhaust Pressure Sensor and with a DVOM (Digital Volt-Ohm Meter) check the power circuit for 5 volts. If there are 12 volts in the sensor instead of 5, the wires from the PCM to the sensor are short, repair it.
• If the above test is OK, measure to check that there are 5 volts in the Exhaust Pressure Sensor signal circuit. 5 volts must be present. If not, there are wiring problems.
• Make sure there's good ground.
• Replace the Exhaust Pressure Sensor.