P047A OBD Error Code: Problem & Solutions

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The P047A trouble code can be identified as Exhaust Pressure Sensor 'B' Circuit.

 

This fault code would start appearing when the incoming signal from the exhaust pressure sensor is not matching intake manifold pressure or ambient air pressure. This can occur due to an electrical circuit fault or sometimes it can be due to mechanical reasons.

The Exhaust Back Pressure (EBP) sensor produces a linear analog voltage signal which indicates pressure when a 5-volt reference signal is supplied to it from the engine control module. It is a variable capacitance sensor. The main function of the EBP sensor is to measure exhaust back pressure so that the exhaust back pressure regulator can be controlled by the engine control module as per the requirement.

 

What causes this problem with the Exhaust Pressure Sensor 'B' Circuit?

 

• The tube from the exhaust manifold to the pressure sensor might have blockage
• Issue of exhaust gas recirculation system / air inlet / charge air leaks
• Some faults in the exhaust gas pressure sensor
• The powertrain control module might have been defective
• Defaults in the exhaust back pressure sensor 'B'
• There might be open or shorted exhaust back pressure sensor 'B' harness
• Exhaust Back Pressure Sensor 'B' circuit might have bad electrical connection

1. Turbocharger - Did your mechanic just found out that there is some fault in the Turbocharger? Buy top notch Turbocharger from us at economical prices.
2. Exhaust Manifold - A broken Exhaust Manifold can cause a lot of issues. It would be nice if you get it replaced on time.
3. Powertrain Control Module - Everything is fine with the Exhaust Manifold and still OBD code P047A flashing? Then there is definitely some fault with the Powertrain Control Module. Get it checked and replace if needed.
4. EGR Valve Gasket - EGR Valve Gasket is an important car part which should never be neglected. May be there is some fault in it due to which P047A code may start flashing.
5. Supercharger - A faulty Supercharger can be troublesome. You can always rely on us as we have best auto parts for our customers.
6. Fuel Pressure Sensor - If everything is alright with PCM, then there is surely some defect in Fuel Pressure Sensor. Get it replaced before the situation gets worse.
7. Manifold Absolute Pressure Sensor - P047A code can display due to some issues in the Manifold Absolute Pressure Sensor. So, it is very important to replace the defective Manifold Absolute Pressure Sensor with us at equitable prices.

Our main motive is to achieve customer satisfaction as for us our customers are everything and that’s why we will help you to diagnose P047A code by mentioning some major symptoms below:

 

Common Symptoms

 

• Illumination of the check engine light
• There might be lack of power
• Unable to perform manual regeneration – burn off the soot out of the particulate filter. Looks like a catalytic converter but has temp sensors and pressure sensor probes inserted into it
• If unable to perform regeneration, eventually may become a crank-no start

If you wish to correct this fault code, then you have to follow certain steps. Correcting a problem needs your careful attention. Here are some ways with the help of which you will be able to correct the OBD Code P047A:

 

• If there is blockage in the tube from the exhaust manifold to the pressure sensor, then it should be corrected
• Replace or repair the exhaust gas recirculation system
• Make sure to repair the faulty exhaust gas pressure sensor
• The defective powertrain control module should be replaced
• Restore the quirky exhaust back pressure sensor 'B'

However, if you face any issue then we have stocked a wide range of best priced harness, manifold pressure, tire pressure gauge, oil pressure sensor, turbo kit and more to help you out in fixing your car.

Here are some steps which you should follow in order to diagnose this fault code:

 

A good starting point is always a technical service bulletin search for your particular vehicle. The vehicle manufacturer may have a PCM flash/reprogram to cover this issue, and it pays to check on this before you find you’ve gone down a long/wrong path.

 

The next step would be to locate the exhaust pressure sensor on your particular vehicle. Once located, disconnect the tube that connects the sensor to the exhaust manifold. Attempt to blow through it. If you are not able to do that, try to run a small piece of wire through it to dislodge the carbon that is trapped inside, causing the fault code you are encountering. If the tube is clear and free, then you must visually inspect the connectors and wiring. Look for chafing, rubbing, bare wires, burn spots or melted plastic. The connectors should be pulled apart and carefully inspect the terminals (the metal parts) inside the connectors. See if they look corroded, burnt or possibly green in color versus the normal metal color you are probably used to seeing. You can get some electrical contact cleaner at any parts store if cleaning of the terminals is needed. If this is not possible, find some 91% rubbing alcohol and a light plastic bristle brush to clean them with. After that you should let the air dry, get some dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and put some where the terminals come into contact. Next, make sure that the tube that connects the turbocharger to the intake manifold is not leaking. Visually inspect all tube connections around the turbocharger and intake manifold. Tighten all hose as well as band clamps.

 

If you have a scan tool, clear the diagnostic trouble codes from memory, and see if this code returns. If it does not, then there is surely some issue in the connections.

 

If the code does return, we will need to test the sensor and as well as the circuits with are related to it. There are 3 wires at the exhaust pressure sensor.

 

Disconnect the harness going to the exhaust pressure sensor. You should use a digital volt ohm meter to test the 5V power supply circuit going to the sensor to insure it is being powered up. If there is 12 volts to the sensor when there should be 5 volts, repair the wiring from the PCM to the sensor for a short to 12 volts, or possibly a bad powertrain control module.

 

If you think it's fine, then use a DVOM check to make sure you have 5V on the exhaust pressure sensor signal circuit. If there is no 5 volts to the sensor, or if you see 12 volts to the sensor, repair the wiring from the PCM to the sensor, or once again a possible bad PCM.

 

Then check to make sure you have a good ground at the exhaust pressure sensor. Connect a test light to 12V battery positive (red terminal) and touch the other end of the test light to the ground circuit going to the exhaust pressure sensor circuit ground. If the test light does not light up, this would indicate the problem circuit. If it does light up, wiggle the wiring harness going to each sensor to see if the test light flickers, indicating an intermittent connection.

 

If all tests have passed so far, and you continue to get a P047A code, this would most likely indicate a faulty exhaust pressure sensor, although a failed PCM could not be ruled out until you replace the sensor

 

Common Mistakes When Diagnosing The P047A Code

 

• Failure in the exhaust pressure sensor
• Defective powertrain control module
• There might be some issues related to the wiring