Dtc P0402 - Mazda 6 Workshop Manual

Diagnostic procedure
STEP
1 VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
• Has FREEZE FRAME DATA been recorded?
2 VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
• Verify related service bulletins and/or on-line
repair information availability.
• Is any related repair information available?
3 INSPECT FOR OTHER DTCS
• Connect the WDS or equivalent to the DLC-2.
• Clear the DTC from the PCM memory using
the WDS or equivalent.
• Turn the engine switch to the ON position.
(Engine off).
• Have other DTCs been stored?
4 INSPECT VACUUM HOSE CONDITION
• Inspect the vacuum hoses for clogging,
damage, freezing, or vacuum leakage.
• Is there any malfunction?
5 INSPECT EGR VALVE MALFUNCTION
• Inspect the EGR valve.
• Is the EGR valve okay?
6 INSPECT EGR BOOST SENSOR
MALFUNCTION
• Inspect the EGR boost sensor.
• Is the EGR boost sensor okay?
7 INSPECT EGR VALVE PASSAGE
• Turn the engine switch off.
• Remove the EGR valve.
• Is gasket installation normal?
8 VERIFY TROUBLESHOOTING OF DTC P0401
COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Connect the WDS or equivalent to the DLC-2.
• Clear the DTC from the PCM memory using
the WDS or equivalent.
• Perform the Repair Verification Drive Mode.
(See F2–39 OBD DRIVE
• Is the PENDING CODE for this DTC present?
9 VERIFY AFTER REPAIR PROCEDURE
• Are any DTCs present?
End Of Sie

DTC P0402

DTC P0402 EGR flow excessive detected
• The PCM monitors the difference between the target air amount and intake air amount while the EGR
system is operating. If the difference between the target air amount and the intake air amount is more than
the threshold, the PCM determines that there is a malfunction in the EGR system.
Diagnostic support note
• The MIL illuminates if the PCM detects above malfunction condition in two consecutive drive cycles or in
DETECTION
CONDITION
one drive cycle while the DTC for the same malfunction has been stored in the PCM.
• PENDING CODE is available if the PCM detects the above malfunction condition during the first drive
cycle.
• FREEZE FRAME DATA is available.
• The DTC is stored in the PCM memory.
• The EGR valve gasket is not installed.
POSSIBLE
• The EGR valve gasket has been damaged.
CAUSE
• PCM malfunction
ON-BOARD DIAGNOSTIC
INSPECTION
MODE.)
Yes Go to the next step.
No Record FREEZE FRAME DATA on repair order, then go to
the next step.
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.
Yes Repair the circuit malfunction for the applicable DTCs.
No Go to the next step.
Yes Replace the vacuum hoses, then go to Step 8.
No Go to the next step.
Yes Go to the next step.
No Replace the EGR valve, then go to Step 8.
Yes Go to the next step.
No Replace the EGR boost sensor, then go to Step 8.
Yes Go to the next step.
No Install the gasket correctly, then go to the next step.
Yes Go to the next step.
No Replace the PCM, then go to the next step.
Yes Go to the applicable DTC inspection.
(See F2–40 DTC TABLE.)
No Troubleshooting completed.
ACTION
B6E407000400102
F2–125
F2