P0401 · Manufacturer communications

RAM · 2026-07-17

Air Handling Performance Test (APT) Availability In wiTECH Technicians may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0234-00 - Turbocharger Overboost Condition. ● P0299-00 - Turbocharger Underboost. ● P0101-00 - Mass Air Flow Sensor "A" Circuit Performance. ● P2463-00 - Diesel Particulate Filter Restriction - Soot Accumulation Bank 1. ● P24A4-00 - Particulate Filter Restriction - Soot Accumulation Too High. ● P2262-00 - Turbocharger Boost Pressure Not Detected - Mechanical. ● P0471-00 - Exhaust Pressure Sensor 1 Performance. ● P1451-00 - Diesel Particulate Filter System Performance. ● P2457-00 - Exhaust Gas Recirculation Cooling System Performance. ● P2263-00 - Turbo…

RAM · 2026-07-11

Air Handling Performance Test (APT) Availability In wiTECH Technicians may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0234-00 - Turbocharger Overboost Condition. ● P0299-00 - Turbocharger Underboost. ● P0101-00 - Mass Air Flow Sensor "A" Circuit Performance. ● P2463-00 - Diesel Particulate Filter Restriction - Soot Accumulation Bank 1. ● P24A4-00 - Particulate Filter Restriction - Soot Accumulation Too High. ● P2262-00 - Turbocharger Boost Pressure Not Detected - Mechanical. ● P0471-00 - Exhaust Pressure Sensor 1 Performance. ● P1451-00 - Diesel Particulate Filter System Performance. ● P2457-00 - Exhaust Gas Recirculation Cooling System Performance. ● P2263-00 - Turbo…

JEEP · 2026-04-18

Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P0300 - Multiple Cylinder Misfire - In Active or Stored status set during cold start catalyst heating. ● P0301 - Cylinder 1 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0302 - Cylinder 2 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0303 - Cylinder 3 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0304 - Cylinder 4 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0305 - Cylinder 5 Misfire - In Active or Stored status set during cold…

RAM · 2025-10-24

Air Handling Performance Test (APT) Availability In wiTECH Technicians may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0234-00 - Turbocharger Overboost Condition. ● P0299-00 - Turbocharger Underboost. ● P0101-00 - Mass Air Flow Sensor "A" Circuit Performance. ● P2463-00 - Diesel Particulate Filter Restriction - Soot Accumulation Bank 1. ● P24A4-00 - Particulate Filter Restriction - Soot Accumulation Too High. ● P2262-00 - Turbocharger Boost Pressure Not Detected - Mechanical. ● P0471-00 - Exhaust Pressure Sensor 1 Performance. ● P1451-00 - Diesel Particulate Filter System Performance. ● P2457-00 - Exhaust Gas Recirculation Cooling System Performance. ● P2263-00 - Turbo Boost…

FORD, LINCOLN · 2024-08-27

Some 2024 Edge and 2023 Nautilus vehicles built on 28-Aug-2023 and through 02-Apr-2024 equipped with a 2.0L EcoBoost engine may experience an illuminated malfunction indicator (MIL) with diagnostic trouble codes (DTCs) P0401 or P2457. Various engine cooling system symptoms which may include an internal/external leak, white smoke from the tailpipe, and/or over-temperature warnings may also be present. This may be due to a transmission fluid heater coolant control valve restricting flow and possibly causing the exhaust gas recirculation (EGR) cooler to crack. To correct the condition, follow the Service Procedure to replace the affected parts.

JEEP · 2024-05-17

"Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0401 - EGR System Performance. ● P00FD - Battery B State Of Charge Performance. In addition, the following software enhancement(s) is/are available: ● Enable customers to operate at high state of charge range between 85 to 92%. This bulletin involves reprogramming the PCM with the latest available software."

HYUNDAI · 2023-08-21

This bulletin provides warranty procedure for EGR Valve replacement related to DTC P0401 EGR Flow Insufficient on 2020 and 2021MY Sonata (DN8a) equipped with 2.5 GDI Vehicles.

AUDI · 2023-08-11

This bulletin provides information for when the MIL is on and DTC P040100 is stored in the ECM.

MITSUBISHI · 2023-08-02

This Technical Service Bulletin provides instructions to reprogram the ECU with the countermeasure software when the check engine light illuminates with DTC of P0401/ P0400.

AUDI · 2023-07-25

This bulletin provides information for when the MIL is on and DTC P040100 is stored in the ECM.

AUDI · 2023-07-07

This bulletin provides information for when the MIL is on and DTC P040100 is stored in the ECM.

RAM · 2023-05-24

Flash: Powertrain Control Module (PCM) Updates Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes (DTC)s have been set: ? **P0299 - Turbocharger Underboost.** ? P061B - Internal Control Module Torque Calculation Performance. ? P0755 - Shift Solenoid B (DG7 Only). ? P0765 - Shift Solenoid D (DG7 Only). ? P0401 - EGR System Performance. ? P0755 - 2C Solenoid Circuit. ? P0765 - UD Solenoid Circuit. ? P244A - Diesel Particulate Filter Differential Pressure Too Low. ? P20EE - SCR NOx Catalyst Efficiency Below Threshold - Bank 1. ? P242F - Diesel Particulate Filter Restriction - Ash Accumulation. ? P1451 - Diesel Particulate Filter System Performance. ? P2463 -…

KIA · 2023-03-06

TECHNICAL SERVICE BULLETIN: MQ4 P/HEV GAMMA 1.6L T-GDI ECM & HCULDC LOGIC IMPROVEMENT FOR OIL DILUTION: This bulletin provides the procedure to update the software logic of the 'Engine' and Hybrid Control Unit Low DC-DC Converter 'HCULDC' systems on certain 2021-2023MY Sorento HEV, PHEV (MQ4 P/HEV) w/ Gamma 1.6L T-GDI vehicles produced from July 1, 2021 through November 3, 2022. The affected vehicles may exhibit a MIL 'ON' with DTCs stored (P144100, P1A7795, P00B700, P211800, P040100, P023600, P029900, P2B6000) due to the engine oil becoming diluted with fuel and/or moisture caused by repeated short drive trips, in low outdoor temperature (32 degree F-) environments.

HYUNDAI · 2023-02-27

This bulletin provides information related to the Engine Control Module (ECM) software update for Santa Fe Hybrid (TM HEV) / Santa Fe Plug-In Hybrid (TM PHEV) vehicles to revise the following DTC logic: • P1441(PCSV rear and hose missing) • P1A77(HSG Belt slip) • P00B7(Excessive ITM motor operating current) • P2118 (ETC target position failure) • P0401 (EGR gas flow insufficient) • P0236 (Turbocharger boost sensor range abnormal) • P0299 (Turbocharger boost pressure too low)

NISSAN · 2023-02-23

MIL ON AND DTC P0401 STORED IN THE ECM IF YOU CONFIRM The Malfunction Indicator Lamp (MIL) is ON and DTC P0401 (EGR System) is stored in the ECM. ACTION 1. Inspect the EGR fitting on the intake air duct (Figure 1) for a restriction. 2. Replace the intake air duct if a restriction is present in the EGR fitting.

RAM · 2023-01-12

Flash: Powertrain Control Module (PCM) Updates Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes (DTCs) have been set: **P0299 - Turbocharger Underboost.** P026B-00 - Injection Timing Performance. P061B-00 - Internal Control Module Torque Calculation Performance. P1451-00 - Diesel Particulate Filter System Performance. P0755-00 - Shift Solenoid ?B? (DG7 Trans Sales Code). P0765-00 - Shift Solenoid ?D?(DG7 Only). P0401-00 - EGR System Performance Customers may also experience the following: **Service Exhaust System message in the Electronic Vehicle Information Center (EVIC) with no MIL.** Improvements to cold temperature engine rpm fluctuation. Reduce…

ISUZU · 2022-12-14

Isuzu Motors Limited has determined that certain 2015 model year Isuzu N-Series trucks equipped with 5.2L (4HK1) diesel engines were built with an Engine Control Module (EC) containing an On-Board Diagnostic (OBD) calibration error for Diagnostic Trouble Code (DTC) P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient. As a result, the ECM was not sensitive enough to detect DTC P0401 at the appropriate time, which would normally cause the check engine Malfunction Indicator Light (MIL) to illuminate. Isuzu has corrected the calibration so DTC P0401 can be detected properly.

RAM · 2022-10-25

Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module/Powertrain Control Module (ECM/PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following DTCs have been set: P0299-00 - Turbocharger Underboost. P026B-00 - Injection Timing Performance. P061B-00 - Internal Control Module Torque Calculation Performance. P1451-00 - Diesel Particulate Filter System Performance. P0755-00 - Shift Solenoid "B"(DG7 Trans Sales Code). P0765-00 - Shift Solenoid "D"(DG7 Only). P0401-00 - EGR System Performance. The following improvements are also included in this update:Improvements to cold temperature engine rpm…

NISSAN · 2022-10-14

MIL ON WITH DTC P0401 AND/OR P0404 STORED IN THE ECM This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin.

RAM · 2022-09-10

Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module/Powertrain Control Module (ECM/PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following DTCs have been set: P0401-00 - EGR System Performance. P0299-00 - Turbocharger Underboost (ETM Only). The following improvements are also included in this update: wiTECH Fuel System Run-Up Test routine Improvement. Idle stability Improvement. wiTECH PCM data improvements. wiTECH cylinder cut-out routine, improvement

NISSAN · 2022-07-29

MIL ON WITH DTC P0401 AND/OR P0404 STORED IN THE ECM IF YOU CONFIRM The MIL is ON and DTC P0401 (EGR A FLOW INSUFFICIENT) and/or P0404 (EGR A CONTROL) is stored in the ECM. AND There are no drivability concerns. ACTION 1. Confirm the current ECM part number. 2. Reprogram the ECM, if applicable.

RAM · 2022-07-09

Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module/Powertrain Control Module (ECM/PCM) with the latest available software. The customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following DTCs. P0401 - EGR System Performance. P2281 - Air Leak Between MAF and Throttle Body. P0402 - Egr Flow Excessive Detected. P0234 - Turbocharger Overboost Condition. P049D - Egr Control Position Exceeded Learning Limit. P040B - Exhaust Gas Recirculation Temperature Sensor "A" Circuit Performance. P064F - Unauthorized Software/Calibration Detected. P20EE - SCR NOx Catalyst Efficiency Below Threshold - Bank 1. P1C54 - SCR NOx Catalyst Missing. P229F…

HYUNDAI · 2022-06-03

This bulletin provides information related to the Engine Control Module (ECM) software update for Santa Fe Hybrid (TM HEV) / Santa Fe Plug-In Hybrid (TM PHEV) and Tucson Hybrid (NX4 HEV) / Tucson Plug-In Hybrid (NX4 PHEV) vehicles to revise the following DTC logic: • P1441(PCSV rear and hose missing) • P1A77(HSG Belt slip) • P00B7(Excessive ITM motor operating current) • P2118 (ETC target position failure) • P0401 (EGR gas flow insufficient) • P0236 (Turbocharger boost sensor range abnormal) • P0299 (Turbocharger boost pressure too low)

FORD · 2022-05-17

Certain 2011-2014 Model Year Super Duty Vehicles Equipped with a 6.7L Diesel Engine Exhaust Gas Recirculation Cooler with Diagnostic Trouble Codes P0401 and/or P2457 - In some of the affected vehicles, customers may experience an illuminated malfunction indicator light due to the EGR cooler becoming plugged with hydrocarbon or soot at high mileage. Diagnostic trouble codes (DTC’s) for EGR cooler efficiency below threshold (DTC P0401) and/or insufficient EGR flow at idle (DTC P2457) are stored when the malfunction indicator light is illuminated.

RAM · 2022-05-10

Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module/Powertrain Control Module (ECM/PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or more of the following Diagnostic Trouble Codes (DTCs) have been set: P0401-00 - EGR System Performance. P0299-00 - Turbocharger Underboost (ETM Only). P0755-00 - 2C Solenoid Circuit. P0765-00 - UD Solenoid Circuit. The following improvements are also included in this update: wiTECH PCM data improvements. wiTECH cylinder cut-out routine, improvement

RAM · 2022-05-10

Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module/Powertrain ControlModule (ECM/PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or moreof the following DTCs have been set: P0299 - Turbocharger Underboost. P0401 - EGR System Performance. P0755 - 2C Solenoid Circuit. P0765 - UD Solenoid Circuit. P244A - Diesel Particulate Filter Differential Pressure Too Low. P20EE - SCR NOx Catalyst Efficiency Below Threshold - Bank 1. P242F - Diesel Particulate Filter Restriction - Ash Accumulation. P1451 - Diesel Particulate Filter System Performance. P2463 - Diesel Particulate Filter Restriction - Soot Accumulation Bank…

RAM · 2022-04-12

Flash: Powertrain Control Module (PCM) Updates This bulletin involves reprogramming the Engine Control Module/Powertrain ControlModule (ECM/PCM) with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find that one or moreof the following DTCs have been set: P064F - Unauthorized Software/Calibration Detected. P2706 - MS Solenoid Circuit(68RFE Only). P0868 - Line Pressure Low. P229F - Aftertreatment NOxSensor Circuit Performance - Bank 1 Sensor 2. P207F - Reductant Quality Performance. P2509 - PCM/PCM Power Input Signal Intermittent. P0401 - EGR System Performance. P0870 - OD Hydraulic Pressure Test. P040B - Exhaust Gas Recirculation Temperature Sensor "A" Circuit Performance. P2201 -…

FORD · 2022-01-14

Customer Satisfaction Program 21M04 Certain 2011-2014 Model Year Super Duty Vehicles Equipped with a 6.7L Diesel Engine Exhaust Gas Recirculation Cooler with Diagnostic Trouble Codes P0401 and/or P2457

VOLKSWAGEN · 2021-10-26

Customer states MIL-on with P0087 P0149 P053F in the ECM Customer states MIL-on with any combination of P0300, P0301, P0302, P0303, P0304, P1D74 and/or P1D75 in the ECM Customer states rattle noise from the underbody heat shields Customer states noise from front suspension Customer states noise during clutch pedal operation Customer concern of vehicle door hard to close/out of adjustment Customer states airbag light on Customer states no crank/no start. Vehicle is towed in. Customer states there is a popping/clicking noise while operating temperature settings Customer states MIL-on with P0401

VOLKSWAGEN · 2021-10-13

Customer states MIL-on with P0087 P0149 P053F in the ECM Customer states noise from front suspension Customer states noise during clutch pedal operation Customer concern of vehicle door hard to close/out of adjustment Customer states airbag light on Customer states no crank/no start. Vehicle is towed in. Customer states there is a popping/clicking noise while operating temperature settings Customer states MIL-on with P0401