DTC P0401 [MZ-CD 1.6 (Y6)]
id0102c3815300
|
DTC P0401 |
EGR flow insufficient detected |
|---|---|
|
DETECTION CONDITION
|
• The PCM monitors the MAF sensor signal voltage while EGR system is operating. If the actual MAF signal is above desired signal in PCM, the PCM determines that there is a malfunction in the EGR system.
|
|
POSSIBLE CAUSE
|
• EGR valve malfunction
• EGR flow passage clogged
• EGR gas leakage at flow passage
• Intake throttle valve stuck open
• PCM malfunction
|
Diagnostic procedure
|
STEP |
INSPECTION |
ACTION |
|
|---|---|---|---|
|
1
|
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has the FREEZE FRAME DATA been recorded?
|
Yes
|
Go to the next step.
|
|
No
|
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
|
||
|
2
|
VERIFY REPAIR INFORMATION AVAILABILITY
• Verify related service repair information availability.
• Is any related repair information available?
|
Yes
|
Perform repair or diagnosis according to the available repair information.
If the vehicle is not repaired, go to the next step.
|
|
No
|
Go to the next step.
|
||
|
3
|
IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA
• Is DTC P0401 on FREEZE FRAME DATA?
|
Yes
|
Go to the next step.
|
|
No
|
Go to troubleshooting procedures for DTC in FREEZE FRAME DATA.
|
||
|
4
|
INSPECT OPERATION OF EGR VALVE
• Remove the EGR valve with connector connected.
• Connect the M-MDS to DLC-2.
• Turn the engine switch to the ON position (Engine off).
• Access EgrDc PID.
• Visually inspect the EGR valve operation using the EgrDc PID of simulation function.
• Does the EGR valve move smoothly?
|
Yes
|
Go to Step 6.
|
|
No
|
Clean the EGR valve, then go to the next step.
|
||
|
5
|
INSPECT EGR VALVE
• Inspect the EGR valve.
• Is the EGR valve normal?
|
Yes
|
Go to the next step.
|
|
No
|
Replace the EGR valve, then go to Step 9.
|
||
|
6
|
INSPECT OPERATION OF INTAKE THROTTLE VALVE
• Remove the intake throttle valve with connector connected.
• Connect the M-MDS to DLC-2.
• Turn the engine switch to the ON position (Engine off).
• Access EGR_TV PID.
• Visually inspect the intake throttle valve operation using the EGR_TV PID of simulation function.
• Does the intake throttle valve move smoothly?
|
Yes
|
Go to Step 8.
|
|
No
|
Clean the intake throttle valve, then go to Step 9.
|
||
|
7
|
INSPECT INTAKE THROTTLE VALVE
• Inspect the intake throttle valve.
• Is the intake throttle valve normal?
|
Yes
|
Go to the next step.
|
|
No
|
Replace the air pipe (air bypass valve (High power-Euro 4) and intake throttle valve component), then go to Step 9.
|
||
|
8
|
INSPECT EGR FLOW PASSAGE
• Inspect EGR flow passage.
• Is the EGR flow passage clogged or leakage?
|
Yes
|
Repair or clean EGR flow passage, then go to the next step
|
|
No
|
Go to the next step.
|
||
|
9
|
VERIFY THAT DTC P0401 TROUBLESHOOTING IS COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the M-MDS.
• Start the engine and warm-up to normal operating temperature.
• Retrieve the DTC using the M-MDS.
• Is the PENDING CODE same DTC present?
|
Yes
|
Replace PCM, then go to the next step.
|
|
No
|
Go to the next step.
|
||
|
10
|
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
|
Yes
|
Go to the applicable DTC inspection.
(See DTC TABLE [MZ-CD 1.6 (Y6)].)
|
|
No
|
Troubleshooting completed.
|
||