| DTC Code | DTC Name |
|---|---|
| P04019C | Exhaust Gas Recirculation "A" Low / Insufficient Flow |
DESCRIPTION
Based on the driving conditions, the ECM regulates the volume of exhaust gas that is recirculated to each engine cylinder in order to lower the combustion temperature and reduce NOx emissions. The ECM monitors signals such as engine speed, engine coolant temperature, electric load, and vehicle speed. When the EGR permission conditions are met, the ECM controls the opening of the EGR valve linearly through signals to the EGR step motor.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory | Note |
|---|---|---|---|---|---|---|
| P04019C | Exhaust Gas Recirculation "A" Low / Insufficient Flow | Change in intake manifold pressure is small when the EGR valve opened and closed during fuel cut operation (2 trip detection logic). |
|
Does not come on | DTC stored | SAE Code: P0401 |
MONITOR DESCRIPTION
The ECM monitors the pressure inside the intake manifold while opening and closing the EGR valve during fuel cut operation. If there is no change in the manifold absolute pressure sensor value, the ECM interprets this as a malfunction of the EGR valve assembly, illuminates the MIL and stores this DTC.
MONITOR STRATEGY
| Required Sensors/Components (Main) | EGR valve assembly Manifold absolute pressure sensor |
| Required Sensors/Components (Related) | Engine coolant temperature sensor |
| Frequency of Operation | Once per driving cycle |
TYPICAL ENABLING CONDITIONS
| Engine speed | 1000 to 1800 rpm |
| Vehicle speed | 45 km/h (28 mph) or more |
| Intake air temperature | -10°C (14°F) or higher |
TYPICAL MALFUNCTION THRESHOLDS
| Manifold pressure change | Less than 2.03 kPa [2.94 psi] |
| At engine speed | 1400 rpm |
CONFIRMATION DRIVING PATTERN
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [A].
Drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more [B].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Idle the engine for 30 seconds or more [C].
With the shift lever in S, accelerate the vehicle to 80 km/h (50 mph) or more [D].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Perform the fuel cut operation for 5 seconds or more, with the accelerator pedal fully released [E].
Repeat steps [D] through [E] above 3 times in one driving cycle.
Enter the following menus: Powertrain / Engine / Trouble Codes [F].
Read the pending DTCs.
Tech Tips
If a pending DTC is output, the system is malfunctioning.
If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC P04019C.
Check the DTC judgment result.
| GTS Display | Description |
|---|---|
| NORMAL |
|
| ABNORMAL |
|
| INCOMPLETE |
|
Tech Tips
If the judgment result is NORMAL, the system is normal.
If the judgment result is ABNORMAL, the system has a malfunction.
If the judgment result is INCOMPLETE, perform steps [D] through [F] again.
CAUTION / NOTICE / HINT
Tech Tips
By using the Control the EGR Step Position Active Test, the operation of the EGR valve can be checked.
When the engine is idling steadily with the EGR valve fully closed, if the EGR valve is normal and it is opened using the Active Test, the Data List value changes as follows.
| Data List Item | Change in Data List when Number of Steps is Increased Using Control the EGR Step Position Active Test |
|---|---|
| Engine Speed | Idle becomes rough |
| Intake Manifold Absolute Pressure | Pressure rises |
Read Freeze Frame Data using the GTS. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. When troubleshooting, Freeze Frame Data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P04019C)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
Tech Tips
If any DTCs other than P04019C are output, troubleshoot those DTCs first.
| B |
|
GO TO DTC CHART Click here |
| A |
|
READ VALUE USING GTS (INTAKE MANIFOLD ABSOLUTE PRESSURE)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Data List / Intake Manifold Absolute Pressure.
| Tester Display |
|---|
| Intake Manifold Absolute Pressure |
Read the value of Intake Manifold Absolute Pressure.
| Standard | ||||
|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here |
| OK |
|
PERFORM ACTIVE TEST USING GTS (CONTROL THE EGR STEP POSITION)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.
Tech Tips
The A/C switch and all accessories should be off.
Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Intake Manifold Absolute Pressure and Coolant Temperature.
| Active Test Display |
|---|
| Control the EGR Step Position |
| Data List Display |
|---|
| Intake Manifold Absolute Pressure |
| Coolant Temperature |
According to the display on the GTS, compare the values of Data List item Intake Manifold Absolute Pressure before and while performing the Active Test.
Note
Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.
| Standard | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| The value of Intake Manifold Absolute Pressure changes according to the EGR valve step set by the Active Test. | |||||||||||
|
|||||||||||
Tech Tips
While performing the Active Test, if the increase in the value of Intake Manifold Absolute Pressure is small, the EGR valve assembly may be malfunctioning.
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| B |
|
REPLACE EGR VALVE ASSEMBLY Click here |
| C |
|
CLEAR DTC Click here |
| A |
|
CHECK INTAKE SYSTEM
Check the intake system for vacuum leaks.
| OK |
|---|
| No leaks from intake system. |
Tech Tips
Perform "Inspection After Repair" after repairing or replacing the intake system.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE INTAKE SYSTEM |
| OK |
|
INSPECT EGR VALVE ASSEMBLY
Remove the EGR valve assembly.
Check if the EGR valve is stuck open.
| OK |
|---|
| EGR valve is tightly closed. |
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here |
| NG |
|
REPLACE EGR VALVE ASSEMBLY Click here |
REPLACE EGR VALVE ASSEMBLY
Replace the EGR valve assembly.
| Result | ||
|---|---|---|
|
| NEXT |
|
CLEAR DTC
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Turn the ignition switch off and wait for at least 30 seconds.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P04019C)
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
END |
| B |
|
REPLACE EGR COOLER ASSEMBLY
Replace the EGR cooler assembly.
Tech Tips
If any of the EGR system related pipes (EGR pipe, exhaust manifold, etc.) are cracked, damaged or clogged, replace them as necessary.
Perform "Inspection After Repair" after replacing the EGR system.
| Result | ||
|---|---|---|
|
| NEXT |
|
CLEAR DTC
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Turn the ignition switch off and wait for at least 30 seconds.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P04019C)
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Read the DTCs.
| OK |
|---|
| DTCs are not output. |
| Result | ||
|---|---|---|
|
| NEXT |
|
END |
CLEAR DTC
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Turn the ignition switch off and wait for at least 30 seconds.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P04019C)
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| A |
|
END |
| B |
|
REPLACE EGR VALVE ASSEMBLY Click here |