SFI SYSTEM, Diagnostic DTC:P0400
| DTC Code | DTC Name |
|---|---|
| P0400 | Exhaust Gas Recirculation Flow |
DESCRIPTION
The EGR (Exhaust Gas Recirculation) system recirculates exhaust gases, which are controlled to the proper volume in accordance with driving conditions. The recirculated gas mingles with the intake air, therefore slowing down the engine combustion and lowering the combustion temperature. This helps reduce nitrogen oxide (NOx) emissions.
In order to increase circulation, the ECM adjusts the lift of the EGR valve and intake shutter valve (throttle valve).
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
MIL |
Memory |
|---|---|---|---|---|---|
P0400 |
Exhaust Gas Recirculation Flow |
Target and actual manifold absolute pressure rates differ (3 trip detection logic). |
|
Comes on |
DTC stored |
If DTC P0403 has already been stored, P0400 is not stored.
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
DTC P0400 is stored while the engine is in fuel cut condition for 4 seconds or more and the brake pedal is pressed for approximately 2 seconds.
CAUTION / NOTICE / HINT
Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
CHECK ANY OTHER DTC OUTPUT (IN ADDITION TO DTC P0400)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT/ Trouble Codes.
Read the DTC.
Powertrain > Engine and ECT > Trouble Codes
Result
Result
Proceed to
DTC P0400 is output
A
DTC P0400 and P0403 is output
B
PERFORM ACTIVE TEST USING GTS (CONTROL THE EGR STEP POSITION)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tip:When performing the Active Test, make sure the shift lever is in Neutral position.
The A/C switch and all accessory switches should be off.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / All Data / MAP and Throttle Position.
Powertrain > Engine and ECT > Active Test
Active Test Display
Control the EGR Step Position
Data List Display
MAP
Throttle Position
Confirm that Throttle Position is ON and check the engine idling condition and the value of MAP in the Data List while performing the Active Test.
Tip: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.
Do not open the EGR valve 20 steps or more during Active Test.
OK
MAP and idling condition change in response to EGR step position as follows.
Standard
-
EGR Step Position (Active Test)
0 Steps
0 to 20 Steps
Idling condition
Steady idling
Idling changes from steady to rough idling or engine stalls
MAP value
(Data List)
29 to 37 kPa
(EGR valve is fully closed)
MAP value is at least +10 to 15 kPa higher than when EGR valve is fully closed
Tip:During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in EGR valve.
EGR Valve is Sticking in Close Side
-
EGR Step Position (Active Test)
0 Steps
20 Steps
Idling condition
Steady idling
Steady idling
EGR Valve is Sticking in Open Side
-
EGR Step Position (Active Test)
0 Steps
20 Steps
Idling condition
Rough idling or engine stall
(Engine difficult to start)
Rough idling or engine stall
(Engine difficult to start)
Result
Proceed to
OK
NG
NG CHECK HARNESS AND CONNECTOR (EGR VALVE ASSEMBLY - ECM - EFI-MAIN RELAY)Click here
READ VALUE USING GTS (MAP)
Connect the GTS to the DLC3.
Start the engine.
Turn the GTS on.
Warm up the engine.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAP.
Powertrain > Engine and ECT > Data List
Tester Display
MAP
Read the MAP value at racing the engine.
Standard
Condition
Specified Condition
Ignition switch ON
80 to 110 kPa
Racing the engine
Changes in response to accelerator pedal operation
Result
Proceed to
OK
NG
NG INSPECT VACUUM HOSEClick here
CHECK FOR DEPOSIT (EXHAUST MANIFOLD CONVERTER TO EGR VALVE ASSEMBLY)
Check for cracks, damage, and clogs in the pipes between the exhaust manifold converter and the EGR valve assembly.
Check for exhaust leaks at each connection point.
Tip:This check may require the removal of components.
OK
No deposit
Result
Proceed to
OK
NG
NG REPAIR OR REPLACE MALFUNCTIONING PARTS
CHECK FOR DEPOSIT (EGR VALVE ASSEMBLY TO INTAKE PORT)
Check for cracks, damage, and clogs in the pipes between the intake port and the EGR valve assembly.
Check for exhaust leaks at each connection point.
Tip:This check may require the removal of components.
OK
No deposit
Result
Proceed to
OK
NG
NG REPAIR OR REPLACE MALFUNCTIONING PARTS
REPLACE EGR VALVE ASSEMBLY
Replace the EGR valve assembly
Result
Proceed to
NEXT
CHECK WHETHER DTC OUTPUT RECURS (DTC P0400)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs
Turn the ignition switch off and wait for at least 30 seconds.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tip:The A/C switch and all accessory switches should be off.
Turn the GTS on.
Drive the vehicle at 60 to 80 km/h (37 mph to 50 mph) with the shift lever in the 3rd position.
CAUTION:When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Perform fuel-cut operation for 4 seconds or more, with the accelerator pedal fully released and the brake pedal pressed.
Tip:If the vehicle speed becomes lower than 40 km/h (25 mph) within 4 seconds, perform the confirmation driving pattern again.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the pending DTCs.
Powertrain > Engine and ECT > Trouble Codes
Result
Result
Proceed to
DTC P0400 is output
A
DTCs are not output
B
B END
INSPECT VACUUM HOSE
Vacuum hose is connected correctly and is not damaged.
If a hose is damaged do not repair by cutting, and replace with a new part.
Result
Proceed to
OK
NG
NG REPLACE VACUUM HOSE
CHECK HARNESS AND CONNECTOR (EGR VALVE ASSEMBLY - ECM - EFI-MAIN RELAY)
Disconnect the EGR valve assembly connector.
Disconnect the ECM connector.
Disconnect the driver side junction block assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection
Condition
Specified Condition
B23-4 (EGR1) - B31-29 (EGR1)
Always
Below 1 Ω
B23-3 (EGR2) - B31-28 (EGR2)
Always
Below 1 Ω
B23-6 (EGR3) - B31-59 (EGR3)
Always
Below 1 Ω
B23-1 (EGR4) - B31-58 (EGR4)
Always
Below 1 Ω
3K-5 - B23-5 (+B1)
Always
Below 1 Ω
3K-5 - B23-2 (+B2)
Always
Below 1 Ω
B23-4 (EGR1) or B31-29 (EGR1) - Body ground
Always
10 kΩ or higher
B23-3 (EGR2) or B31-28 (EGR2) - Body ground
Always
10 kΩ or higher
B23-6 (EGR3) or B31-59 (EGR3) - Body ground
Always
10 kΩ or higher
B23-1 (EGR4) or B31-58 (EGR4) - Body ground
Always
10 kΩ or higher
B23-5 (+B1) or B23-2 (+B2) - Body ground
Always
10 kΩ or higher
Result
Proceed to
OK
NG
NG REPAIR OR REPLACE HARNESS OR CONNECTOR
CHECK WHETHER DTC OUTPUT RECURS (DTC P0400)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs
Turn the ignition switch off and wait for at least 30 seconds.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tip:The A/C switch and all accessory switches should be off.
Turn the GTS on.
Drive the vehicle at 60 to 80 km/h (37 mph to 50 mph) with the shift lever in the 3rd position.
CAUTION:When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Perform fuel-cut operation for 4 seconds or more, with the accelerator pedal fully released and the brake pedal pressed.
Tip:If the vehicle speed becomes lower than 40 km/h (25 mph) within 4 seconds, perform the confirmation driving pattern again.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the pending DTCs.
Powertrain > Engine and ECT > Trouble Codes
Result
Result
Proceed to
DTC P0400 is output
A
DTCs are not output
B
REPLACE EGR VALVE ASSEMBLY
Replace the EGR valve assembly.
Result
Proceed to
NEXT
CHECK WHETHER DTC OUTPUT RECURS (DTC P0400)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs
Turn the ignition switch off and wait for at least 30 seconds.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tip:The A/C switch and all accessory switches should be off.
Turn the GTS on.
Drive the vehicle at 60 to 80 km/h (37 mph to 50 mph) with the shift lever in the 3rd position.
CAUTION:When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Perform fuel-cut operation for 4 seconds or more, with the accelerator pedal fully released and the brake pedal pressed.
Tip:If the vehicle speed becomes lower than 40 km/h (25 mph) within 4 seconds, perform the confirmation driving pattern again.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the pending DTCs.
Powertrain > Engine and ECT > Trouble Codes
Result
Result
Proceed to
DTC P0400 is output
A
DTCs are not output
B
B END