DTC P0401: Exhaust Gas Recirculation (EGR) Flow Insufficient: Troubleshooting

TROUBLESHOOTING CHART

Step	Action	Value(s)	Yes	No
1	Perform an On-Board Diagnostic (OBD II) System Check. Was the check performed?	-	Go to Step 2	Go to On-Board Diagnostic (OBD II) System Check
2	Install a scan tool to the Data Link Connector (DLC). Start the engine and allow the engine to idle. Command the Exhaust Gas Recirculation (EGR) valve to the specific value. Does the engine stall or attempt to stall?	50%	Go to Step 5	Go to Step 3
3	Turn the ignition OFF. Disconnect the EGR valve connector and remove the EGR valve. Inspect the EGR valve passages and pipe for a restriction or damages and repair as needed. Is the repair complete?	-	Go to Step 5	Go to Step 4
4	Replace the EGR valve. Is the repair complete?	-	Go to Step 5	-
5	Disconnect the battery for more than 10 seconds. Drive the vehicle up to 97 km/h (60 mph). Release the throttle and allow the vehicle to decelerate to 32 km/h (20 mph). Is the EGR Decel Filter value greater than specified value?	0	Go to Step 3	Go to Step 6
6	Using the scan tool, clear the Diagnostic Trouble Codes (DTCs). Start the engine and idle at normal operating temperature. Operate the vehicle within the Conditions for setting this DTC as specified in the supporting text. Does the scan tool indicate that this diagnostic has run and passed?	-	Go to Step 7	Go to Step 2
7	Check if any additional DTCs are set. Are any DTCs displayed that have not been diagnosed?	-	Go to applicable DTC table	System OK