M20F-FXS, M20G-FXS ENGINE CONTROL SFI SYSTEM 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 | 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). | ·
EGR valve assembly ·
EGR passage ·
EGR cooler assembly ·
Intake system ·
Manifold absolute pressure sensor |
Comes on | 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 | 950 to 1600 rpm |
| Vehicle speed | 20 km/h (13 mph) or more |
| Intake air temperature | -10°C (14°F) or higher |
TYPICAL MALFUNCTION THRESHOLDS
| Manifold pressure change | Less than 1.72 kPa [0.25 psi] |
| At engine speed | 1000 rpm |
CONFIRMATION DRIVING PATTERN
- HINT:
- ·
After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
·When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
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.
Put the engine in Inspection Mode (Maintenance Mode).
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [A].
With the engine running, accelerate the vehicle to 65 km/h (40 mph) or more by depressing the accelerator pedal for at least 10 seconds [B].
- CAUTION:
-
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
- HINT:
-
When accelerating the vehicle, depress the accelerator pedal more than normal to start the engine.
Idle the engine for 30 seconds or more [C].
With the shift lever in S and the engine running, accelerate the vehicle to 65 km/h (40 mph) or more [D].
- CAUTION:
-
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
- HINT:
-
If the engine stops, further depress the accelerator pedal to restart the engine.
Perform the fuel cut operation for 5 seconds or more, with the accelerator pedal fully released [E].
Enter the following menus: Powertrain / Engine / Trouble Codes [F].
Read the pending DTCs.
- HINT:
- ·
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 | ·
DTC judgment completed ·
System normal |
| ABNORMAL | ·
DTC judgment completed ·
System abnormal |
| INCOMPLETE | ·
DTC judgment not completed ·
Perform driving pattern after confirming DTC enabling conditions |
- HINT:
- ·
If the judgment result is NORMAL, the system is normal.
·If the judgment result is ABNORMAL, the system has a malfunction.
·[A] to [F]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
·When clearing the permanent DTCs, do not disconnect the cable from the auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
- NOTICE:
- ·
Vehicle Control History may be stored in the hybrid vehicle control ECU assembly if the engine is malfunctioning. Certain vehicle condition information is recorded when Vehicle Control History is stored. Reading the vehicle conditions recorded in both the Freeze Frame Data and Vehicle Control History can be useful for troubleshooting.
(Select Powertrain in Health Check and then check the time stamp data.)
·If any "Engine Malfunction" Vehicle Control History item has been stored in the hybrid vehicle control ECU assembly, make sure to clear it. However, as all Vehicle Control History items are cleared simultaneously, if any Vehicle Control History items other than "Engine Malfunction" are stored, make sure to perform any troubleshooting for them before clearing Vehicle Control History.
- HINT:
- ·
By using the Control the EGR Step Position Active Test, the operation of the EGR valve can be checked.
·If the EGR valve is normal and 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 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
Read the DTCs.
- Powertrain > Engine > Trouble Codes
- 50001 372
- Result:
Result Proceed to DTC P04019C is output A DTC P04019C and other DTCs are output B
- HINT:
-
If any DTCs other than P04019C are output, troubleshoot those DTCs first.
A
B
Enter the following menus.
- Powertrain > Engine > Data List
-
Tester Display Intake Manifold Absolute Pressure - 50003 372 385
Read the value of Intake Manifold Absolute Pressure.
- Standard:
GTS Display Specified Condition Intake Manifold Absolute Pressure 80 to 110 kPa (11.6 to 15.95 psi)
- Result:
Proceed to OK NG
OK
NG
Put the engine in Inspection Mode (Maintenance Mode).
- Powertrain > Hybrid Control > Utility
-
Tester Display Inspection Mode - 50005 397 2103
Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.
- HINT:
-
The A/C switch and all accessories should be off.
Enter the following menus.
- Powertrain > Engine > Active Test
-
Active Test Display Control the EGR Step Position -
Data List Display Intake Manifold Absolute Pressure Coolant Temperature Engine Independent - 50004 372 25 385,205,428
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.
- NOTICE:
- ·
Make sure that the value of Data List item Engine Independent is "Operate" while performing the Active Test.
·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.
Data List Control the EGR Step Position (Active Test) Before Active Test
(Engine idling)0 Steps 0 to 30 Steps
(Engine idling)Intake Manifold Absolute Pressure 20 to 40 kPa (2.9 to 5.8 psi) (EGR valve is fully closed) Intake Manifold Absolute Pressure value is at least +10 kPa (1.45 psi) higher than when EGR valve is fully closed
- HINT:
- ·
If the value of Data List item Engine Independent is "Not Opr" when the engine is idling, charge control is being performed. Perform the Active Test after charge control is complete ("Operate" is displayed).
·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.
·Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of Intake Manifold Absolute Pressure may occur while performing the Active Test. However, the amount that the value of Intake Manifold Absolute Pressure increases will be smaller than normal.
- Result:
Result Proceed to Before performing the Active Test (while the engine is idling), the value of Intake Manifold Absolute Pressure is not between 20 to 40 kPa (2.9 to 5.8 psi). A When performing the Active Test to change the EGR valve step between 0 (EGR valve fully closed) and 30, the value of Intake Manifold Absolute Pressure changes less than 10 kPa (1.45 psi). B Other than above C
A
B
C
Check the intake system for vacuum leaks.
- OK:
No leaks from intake system.
- HINT:
-
Perform "Inspection After Repair" after repairing or replacing the intake system.
- Result:
Proceed to OK NG
OK
NG
Remove the EGR valve assembly.
Check if the EGR valve is stuck open.
- OK:
EGR valve is tightly closed.
- HINT:
-
Perform "Inspection After Repair" after replacing the EGR valve assembly.
- Result:
Proceed to OK NG
OK
NG
- HINT:
-
Perform "Inspection After Repair" after replacing the EGR valve assembly.
- Result:
Proceed to NEXT
NEXT
Clear the DTCs.
- Powertrain > Engine > Clear DTCs
- 50002 372
Turn the ignition switch off and wait for at least 30 seconds.
- Result:
Proceed to NEXT
NEXT
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Read the DTCs.
- Powertrain > Engine > Trouble Codes
- 50001 372
- Result:
Result Proceed to DTCs are not output A DTC P04019C is output B
A
B
- HINT:
- ·
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:
Proceed to NEXT
NEXT
Clear the DTCs.
- Powertrain > Engine > Clear DTCs
- 50002 372
Turn the ignition switch off and wait for at least 30 seconds.
- Result:
Proceed to NEXT
NEXT
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Read the DTCs.
- Powertrain > Engine > Trouble Codes
- 50001 372
- OK:
DTCs are not output.
- Result:
Proceed to NEXT
NEXT
Clear the DTCs.
- Powertrain > Engine > Clear DTCs
- 50002 372
Turn the ignition switch off and wait for at least 30 seconds.
- Result:
Proceed to NEXT
NEXT
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Read the DTCs.
- Powertrain > Engine > Trouble Codes
- 50001 372
- Result:
Result Proceed to DTCs are not output A DTC P04019C is output B
- HINT:
-
Perform "Inspection After Repair" after replacing the EGR valve assembly.
A
B