DTC P0400: Exhaust Gas Recirculation Flow; DTC P0401: Exhaust Gas Recirculation Flow Insufficient Detected; DTC P0402: Exhaust Gas Recirculation Flow Excessive Detected [08/2022 - ]: Procedure

CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0400, P0401 AND/OR P0402)

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the DTCs.

Result

Result	Proceed to
DTC P0400, P0401 and/or P0402 is output	A
DTC P0400, P0401 and/or P0402 and other DTCs are output	B

HINT:

If any DTCs other than P0400, P0401 and/or P0402 are output, troubleshoot those DTCs first.

Result:

GO TO DTC CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2022 - ]

Result:

See step 2

PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE EGR VALVE)

Connect the Techstream to the DLC3.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
HINT:
- When performing the Active Test, make sure the shift lever is in P or N.
- The A/C switch and all accessory switches should be off.
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

Confirm that Throttle Idle Position is ON and check the engine idling condition and the value of MAP in the Data List while performing the Active Test.

HINT:

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.

MAP and idling condition change in response to EGR step position as follows.

Standard

-	EGR Step Position (Active Test)
-	Step 0	Step 0 to 30
Idling condition	Steady idling	Idling changes from steady to rough idling or engine stalls
MAP (Data List)	-	MAP value is at least 10 kPa (75 mmHg) higher than when EGR valve is fully closed

Result

Proceed to
OK
NG

Result:

See step 4

Result:

See step 3

INSPECT EGR VALVE ASSEMBLY

Confirm that there are no deposits on the EGR valve.

Confirm that the EGR valve is closed.

There are no deposits and the valve is closed.

Result

Proceed to
OK
NG

Result:

See step 4

Result:

See step 5

REPLACE EGR VALVE ASSEMBLY

Replace the EGR valve assembly.

Refer to REMOVAL [08/2015 - ]

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system.

Refer to INITIALIZATION [08/2015 - ]

Result

Proceed to
NEXT

Result:

See step 5

CHECK FOR DEPOSIT (EGR VALVE ASSEMBLY TO INTAKE PORT)

Check for exhaust leaks at each connection point.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check for cracks, damage and blockage of the pipes between the intake manifold converter and EGR valve assembly.
HINT:

This check may require the removal of components.

Check for blockage due to deposits in the EGR valve and pipes.

No deposits.

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE MALFUNCTIONING PARTS

Result:

See step 6

CLEAR CHECK FOR DEPOSIT (EXHAUST MANIFOLD CONVERTER TO EGR VALVE ASSEMBLY)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check for exhaust leaks at each connection point.
Check for cracks, damage and blockage of the pipes between the exhaust manifold converter and EGR valve assembly.
HINT:

This check may require the removal of components.

Check for blockage due to deposits in the EGR valve and pipes.

No deposits.

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE MALFUNCTIONING PARTS

Result:

See step 7

INSPECT EGR COOLER ASSEMBLY

Check for blockage in the EGR cooler assembly.

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE EGR COOLER ASSEMBLY. Refer to REMOVAL [08/2015 - ]

Result:

See step 8

READ VALUE USING TECHSTREAM (MANIFOLD ABSOLUTE PRESSURE SENSOR)

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Data List / MAP.

Read the MAP value.

Standard

Switch Condition	Techstream Display
Engine switch on (IG)	80 to 110 kPa (600 to 825 mmHg)

Result

Proceed to
OK
NG

Result:

See step 11

Result:

See step 9

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Refer to PROCEDURE - Step 3

No leaks in intake system.

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system.

Refer to INITIALIZATION [08/2015 - ]

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE INTAKE SYSTEM

Result:

See step 10

REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR

Replace the manifold absolute pressure sensor.

Refer to REMOVAL [08/2015 - ]

Result

Proceed to
NEXT

Result:

See step 11

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Clear the DTCs.
Refer to DTC CHECK / CLEAR [08/2015 - ]
Turn the engine switch off and wait for 30 seconds.
Turn the engine switch on (IG) and turn the Techstream on.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
HINT:

The A/C switch and all accessory switches should be off.
Drive the vehicle at 60 km/h (37 mph) for 5 minutes or more.
Idle the engine for 30 seconds or more.
Drive the vehicle at 60 km/h (37 mph).
WARNING:
Strictly observe speed limits and traffic laws when performing the confirmation drive pattern.
Perform fuel cut operation for 5 seconds or more with the accelerator pedal fully released.
HINT:

If the deceleration was not completed, perform the Confirmation Driving Pattern again.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
Read the pending DTCs.
If a pending DTC is output, the system is malfunctioning.
HINT:

If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0400, P0401 or P0402.

Check the DTC judgment result.

RESULT

Techstream 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
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

Result

Proceed to
NEXT

Result:

END