Intention of troubleshooting procedure

WARNING: This page is about a different variant/trim than selected.

Step 1-2
- Perform inspection of each separate part.
Step 3
- Perform inspection of EGR valve passage
Step 4
- Perform a unit inspection of the exhaust gas pressure sensor.
Repair completion verification
- Verify that the primary malfunction is resolved and there are no other malfunctions.

P0401-00: (PCM - VIN Y) TROUBLESHOOTING DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	PURPOSE: INSPECT EGR VALVE CONTROL SYSTEM OPERATION Perform the EGR Valve Operation Inspection. (Refer to EGR VALVE INSPECTION (VIN Y) in the service information.) Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
1		No	Go to the next step.
2	PURPOSE: INSPECT INTAKE AIR SYSTEM FOR AIR SUCTION Inspect for air leakage at the following: Around connection of dynamic pressure turbo and intake manifold NOTE: Engine speed may change when rust penetrating agent is sprayed on the air suction area. Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
2		No	Go to the next step.
3	PURPOSE: INSPECT FOR RESTRICTION OR CLOGGED IN EGR PASSAGE Switch the ignition off. Remove the EGR valve. (Refer to EGR VALVE REMOVAL/INSTALLATION (VIN Y) in the service information.) Visually inspect the EGR passage for clogging and the gasket correctly installed. Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1. (If there is clogging caused by soot in the EGR valve, inspect around the EGR piping and clean or replace it.)
3		No	Go to the next step.
4	PURPOSE: INSPECT EXHAUST GAS PRESSURE SENSOR FOR MALFUNCTION Inspect the applicable part. (Refer to EXHAUST GAS PRESSURE SENSOR INSPECTION (VIN Y) in the service information.) Is the part normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification 1. (Refer to EXHAUST GAS PRESSURE SENSOR REMOVAL/INSTALLATION (VIN Y) in the service information.)
Repair completion verification 1	PURPOSE: VERIFY THAT VEHICLE IS REPAIRED Install/connect the part removed/disconnected during the troubleshooting procedure. Clear the DTC recorded in the memory. (see CLEARING DTC .) Replicate the vehicle conditions at the time the DTC was detected using the following procedure. Implement the repeatability verification procedure. (See REPEATABILITY VERIFICATION PROCEDURE .) Perform the DTC inspection for the PCM. (See DTC INSPECTION .) Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See MALFUNCTION DIAGNOSIS FLOW [CONTROLLER AREA NETWORK (CAN)] .) If the CAN communication is normal, perform the diagnosis from Step 1. If the malfunction recurs, replace the PCM, then go to the next step. (Refer to applicable PCM REMOVAL/INSTALLATION (VIN Y) in the service information.)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	PURPOSE: VERIFY IF OTHER DTCs DISPLAYED Perform the DTC inspection. (See DTC INSPECTION .) Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.