CAR OBD CODES
OBD/DTC Search, e.g.P0401
CAR OBD CODES P0401
P0401 OBD Code Definition:
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
P0401 OBD Code Description:
OBD2 Code P0401 Definition:
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
Possible sumptoms of P0401
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.
Possible Causes
Possible causes of P0401
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 OBD-II Codes
P0400 P0402 P0403
Note: The information on the P0401 error code is purely informative, if you need more useful information, please consult your technician.
B2A04 B1701 B1533 B2075 B1117 B209C B2AD7 B1589 B1021 B0131 B1605 B1064 B1A75 B1703 B1245 OBDII Chassis Codes
C1766 C0655 B1C00 C1877 C1104 C0229 C1908 C1720 C0003 C1211 C1289 C1835 C2778 C1909 C1801 OBDII Network Codes
U0533 U0205 U1052 U0134 U0496 U1014 U1160 U0068 U0014 U1219 U1251 U0476 U0013 U1019 U047A OBDII Powertrain Codes
P076B P0B8A P1243 P260E P0074 P018B P2111 P0A99 P1541 P0BEA P202D P0570 P1760 P2040 P046F