SFI SYSTEM, Diagnostic DTC:P0403

DTC Code	DTC Name
P0403	Exhaust Gas Recirculation Control Circuit

DESCRIPTION

Refer to DTC P0401.

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DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0403	Exhaust Gas Recirculation Control Circuit	Both of the following conditions are met for 1 second or more (1 trip detection logic): (a) The engine is running. (b) When any of terminals EGR1 to EGR4 has a fixed voltage of 0 V.	Open or short in EGR valve assembly circuit EGR valve assembly ECM	Comes on	DTC stored

MONITOR DESCRIPTION

This DTC is designed to detect an open or short in the EGR valve assembly circuit.

If the EGR terminal voltage is low when the EGR terminal output is off, the ECM determines that the EGR valve circuit is malfunctioning.

MONITOR STRATEGY


Frequency of Operation	Continuous

CONFIRMATION DRIVING PATTERN

Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the GTS on [A].
Start the engine and warm it up [B].
Drive the vehicle at 20 km/h (12 mph) or more for 10 minutes [C].

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [D].
Read the pending DTCs.
Tip:
- If a pending DTC is output, the system is malfunctioning.
- 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: P0403.

Check the DTC judgment result.


GTS 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

Tip:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

Note:

Inspect the fuses for circuits related to this system before performing the following procedure.

Tip:

Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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

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 more.

Tip:
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 Idle Position.

Powertrain > Engine and ECT > Active Test


Active Test Display
Control the EGR Step Position


Data List Display
MAP
Throttle Idle Position

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

OK

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


-	EGR Step Position (Active Test)
-	0 Steps	0 to 30 Steps
Idling condition	Steady idling	Idling changes from steady to rough idling or engine stalls
MAP (Data List)	MAP value is 20 to 48 kPa(abs) [150 to 360 mmHg(abs)] (EGR valve is fully closed)	MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

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 30 steps or more during the Active Test.
During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve assembly.

Result


Result	Proceed to
NG	A
OK	B

B

CHECK FOR INTERMITTENT PROBLEMS

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A

INSPECT EGR VALVE ASSEMBLY

Inspect the EGR valve assembly.
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Tip:
Perform "Inspection After Repair" after replacing the EGR valve assembly.

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Result


Proceed to
OK
NG

NG

REPLACE EGR VALVE ASSEMBLY

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OK

CHECK TERMINAL VOLTAGE (POWER SOURCE OF EGR VALVE ASSEMBLY)

*a	Front view of wire harness connector (to EGR Valve Assembly)

Disconnect the EGR valve assembly connector.

Turn the ignition switch to ON.

Measure the voltage according to the value(s) in the table below.

Standard Voltage


Tester Connection	Condition	Specified Condition
B69-5 (+B1) - Body ground	Ignition switch ON	11 to 14 V
B69-2 (+B2) - Body ground	Ignition switch ON	11 to 14 V

Result


Result
OK
NG

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (EGR VALVE ASSEMBLY - EFI-MAIN RELAY)

OK

CHECK HARNESS AND CONNECTOR (EGR VALVE ASSEMBLY - ECM)

Disconnect the EGR valve assembly connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
B69-4 (EGR1) - B31-28 (EGR1)	Always	Below 1 Ω
B69-3 (EGR2) - B31-27 (EGR2)	Always	Below 1 Ω
B69-6 (EGR3) - B31-26 (EGR3)	Always	Below 1 Ω
B69-1 (EGR4) - B31-25 (EGR4)	Always	Below 1 Ω
B69-4 (EGR1) or B31-28 (EGR1) - Body ground	Always	10 kΩ or higher
B69-3 (EGR2) or B31-27 (EGR2) - Body ground	Always	10 kΩ or higher
B69-6 (EGR3) or B31-26 (EGR3) - Body ground	Always	10 kΩ or higher
B69-1 (EGR4) or B31-25 (EGR4) - Body ground	Always	10 kΩ or higher

Result


Proceed to
OK
NG

OK

REPLACE ECM

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NG

REPAIR OR REPLACE HARNESS OR CONNECTOR