What is the voltage spec for my DPFE sensor?

Exhaust gas recirculation module check:


1. Note the Differential Pressure Feedback Exhaust Gas Recirculation (DPFE) sensor voltage through the scan tool or backprobe the Brown/Light Green (BN/LG) wire of the Exhaust Gas Recirculation System Module (ESM). Voltage should indicate a reading of 0.5-1.2 volts.

2. If the voltage of the DPFE sensor is out of range, low or high, disconnect the ESM and note that the voltage of the DPFE sensor circuit should indicate a reading of 5.0 volts.

3. If the DPFE sensor voltage is out of range connected and the reading shows 5.0 volts with the ESM disconnected, reconnect the ESM and verify that the Brown/White (BN/WH) wire shows a 5.0 volt reading and that the Grey/Red (GY/RD) wire shows to be a good ground, indicating a voltage of less than 0.1 volts. If these circuits check to be ok, replace the ESM due to a faulty DPFE sensor.

4. If the DPFE sensor voltage in step 1 is found to be ok, verify that both vacuum hoses to the ESM have full engine vacuum to them when it's running.

5. With the engine idling, backprobe the Brown/Pink (BN/PK) wire and hold it to ground. This should activate the Exhaust Gas Recirculation Vacuum Regulator (EVR) solenoid of the ESM. The EGR valve should open, the engine should run rough, and the DPFE sensor voltage should climb.

6. Replace the ESM for a faulty EGR valve, EVR solenoid, or DPFE sensor if the DPFE sensor or engine does not respond to ground activation of the BN/PK wire

A code P0401 most likely means one or more of the following has happened:

• The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
• There is a blockage in the EGR (tube), most likely carbon buildup
• The EGR valve is faulty
• The EGR valve may not be opening due to a lack of vaccuum

Possible SolutionsIn fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.

• Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
• Clean out the EGR valve and/or tubing to remove deposits
• Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
• Replace the DPFE sensor (with a good quality / OEM one)
• Replace the EGR valve

Hi there:
EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor EGR (DPFE). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0401 code means that OBD detected an insufficient amount of EGR.
You may notice drivability problems such as pinging (a.k.a. pre-ignition knock) when the engine is under load or the vehicle is at higher speeds. There may also be other symptoms.


A code P0401 most likely means one or more of the following has happened:
The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
There is a blockage in the EGR (tube), most likely carbon buildup
The EGR valve is faulty
The EGR valve may not be opening due to a lack of vaccuum

Possible Solutions: In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.
Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
Clean out the EGR valve and/or tubing to remove deposits
Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
Replace the DPFE sensor (with a good quality / OEM one)
Replace the EGR valve

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.


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A code P0401 likely means one ormore of the following has happened:

• The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
• There is a blockage in the EGR (tube), most likely carbon buildup
• The EGR valve is faulty
• The EGR valve may not be opening due to a lack of vacuum

PossibleSolutionsTo fix this code, it is quite commonfor people to just replace the EGR valve only to have the OBD code return. TheEGR valve is not always the culprit.

• Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticeable difference in RPM's with the EGR open
• Clean out the EGR valve and/or tubing to remove deposits
• Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
• Replace the DPFE sensor (with a good quality / OEM one)
• Replace the EGR valve

EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor EGR (DPFE). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0401 code means that OBD detected an insufficient amount of EGR.
Symptoms You may notice drivability problems such as pinging (a.k.a. pre-ignition knock) when the engine is under load or the vehicle is at higher speeds. There may also be other symptoms.
Causes A code P0401 most likely means one or more of the following has happened:

• The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
• There is a blockage in the EGR (tube), most likely carbon buildup
• The EGR valve is faulty
• The EGR valve may not be opening due to a lack of vaccuum

Possible Solutions In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.

• Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
• Clean out the EGR valve and/or tubing to remove deposits
• Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
• Replace the DPFE sensor (with a good quality / OEM one)
• Replace the EGR valve

Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
Clean out the EGR valve and/or tubing to remove deposits
Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
Replace the DPFE sensor (with a good quality / OEM one)
Replace the EGR valve

other problem

Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
Replace the DPFE sensor (with a good quality / OEM one)

DTC P0401 - Insufficient EGR Flow

EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor EGR (DPFE). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0401 code means that OBD detected an insufficient amount of EGR.

Causes: A code P0401 most likely means one or more of the following has happened:
* The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
* There is a blockage in the EGR (tube), most likely carbon buildup
* The EGR valve is faulty
* The EGR valve may not be opening due to a lack of vaccuum

Possible Solutions: In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.
* Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
* Clean out the EGR valve and/or tubing to remove deposits
* Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
* Replace the DPFE sensor (with a good quality / OEM one)
* Replace the EGR valve


DTC P1401 - Differential Pressure Feedback Electronic Sensor circuit High Voltage

I think that you need a new DPFE; first check it, you could also have something restricted. There are ports in the throttle body that can cause this as well. Check THIS LINK.

Hope helps.

Answer P1401 - DPF EGR Sensor Circuit High Voltage Detected The EGR monitor checks the DPFE sensor signal to the PCM for high voltage. The test fails when the average voltage to the PCM goes to a voltage greater than the maximum calibrated value. Possible causes: DPFE circuit open VREF short to PWR Damaged DPFE sensor DPFE circuit short to PWR SIGNAL RTN circuit open Damaged PCM Look at scan data stream for a reading greater than 4.5 volts with the key ON and engine OFF or running. This indicates a hard fault.

A code P0401 most likely means one or more of the following has happened:

•The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
•There is a blockage in the EGR (tube), most likely carbon buildup
•The EGR valve is faulty
•The EGR valve may not be opening due to a lack of vacuum

In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.

•Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticeable difference in RPM's with the EGR open
•Clean out the EGR valve and/or tubing to remove deposits
•Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
•Replace the DPFE sensor (with a good quality / OEM one)
•Replace the EGR valve