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P0473 OBD-II Trouble Code: Exhaust Pressure Sensor High

check engine light

P0473 code definition

The P0472 code identifies an electrical problem related to the exhaust system back pressure sensor circuit. It is often associated with P0471 and P0472 codes.

What the P0473 code means

This code is triggered when the PCM detects an irregular voltage reading from the exhaust system back pressure sensor circuit. The abnormal voltage could be either too high or too low. Exhaust pressure is typically monitored in diesel and turbocharged gasoline engines.

What causes the P0473 code?

There are a couple reasons the P0472 may be displayed:

  • Usually, you’ll see this code because the back pressure tube of your vehicle is clogged
  • The back pressure sensor could also be suffering from a clog
  • Damaged electrical wiring and connectors could also be the reason and, typically, they’ve been burnt and therefore aren’t working correctly
  • There’s a chance the PCM is simply at fault, but this is the least likely reason

What are the symptoms of the P0473 code?

If the P0473 code is stored in the PCM, then the back pressure regulator could be malfunctioning. Depending on the model you drive, some park the regulator in the closed position and others in the open. An obvious symptom that something is wrong is simply if your engine isn’t performing as well as it should be. The reason would be a lack of turbocharger pressure which would then trigger the P0473 code. Aside from seeing a Check Engine Light, another symptom would be seeing the associated codes we covered above.

How does a mechanic diagnose the P0473 code?

A simple PCM reprogram may do the trick and therefore is the best place for a mechanic to start. Next, they’ll move onto the exhaust pressure sensor and check to see if wires or connectors are still completely intact. They may also need to be cleaned.

If it’s not a physical problem, the mechanic should use a scan tool to clear the P0473 code (and any related codes) from memory and check to see if it returns. If they don’t, the connectors were probably to blame. If the code does come back, the sensor and its associated circuits will need to be tested.

The PCM and exhaust pressure sensor will also need to be inspected if all other tests are passed.

Common mistakes when diagnosing the P0473 code

Due to the exhaust back pressure tube possibly being located close to the EGR valve, the P0473 code is frequently mistaken for a problem with it. This type of problem is actually completely different, though.

How serious is the P0473 code?

It’s never a good thing if the wiring in your engine has become frayed or burned, so you should have your car looked at immediately if you see a P0473 code. While the problem may be relatively tame for the moment, it could cause future issues that are more dangerous and expensive to fix. Also, a P0473 code means your vehicle may simply stop working after long enough.

What repairs can fix the P0473 code?

The most common approaches that will work for fixing the problems indicated by a P0473 code are:

  • Checking for and repairing any exhaust leaks
  • Checking for and repairing any wiring or connector problems (they may just need a thorough cleaning too)
  • After repairs that appear to clear the code, the vehicle should be test driven to see if it returns

Additional comments for consideration regarding the P0473 code

The test drive mentioned above is extremely important to do. That’s because certain intermittent conditions could be the problem behind the P0473 code, which means a mechanic may make it disappear, but the fix is actually only temporary. Intermittent conditions can be very tough to diagnose and repair, so you really want the help of an experienced mechanic.

Need help with a P04730 code?

If your vehicle is reporting a P0473 code, let YourMechanic help. Our certified mobile mechanics will meet you at your place of business or home – whatever is most convenient. You can speak with one of our service advisors by calling 1-800-791-6230 or visiting us online. We’ll listen to your problem, describe what we can do, and even provide you a free quote.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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