Up to 08/2009
2GR-FXE ENGINE CONTROL: SFI SYSTEM: P0403: Exhaust Gas Recirculation Control Circuit
P0403 - Exhaust Gas Recirculation Control Circuit
DESCRIPTION
Based on the driving conditions, the ECM regulates the volume of exhaust gas that is recirculated to the engine's combustion chambers and thus lowers the combustion temperature to reduce NOx emissions. The ECM monitors signals such as engine speed, coolant temperature, engine load, and vehicle speed. When the EGR permission conditions are fulfilled, the ECM controls the opening of the EGR valve through signals to the EGR stepper motor.
HINT
DTC P0403 is set when the power switch is on (IG).
MONITOR DESCRIPTION
This DTC is designed to detect an open or short in the EGR valve assembly circuit.
Example:
- If the EGR1, EGR2, EGR3 or EGR4 terminal output voltage is excessively low, but the step motor is still operating, the ECM determines that there is a short in the EGR valve assembly circuit, and sets the DTC.
- If the EGR1, EGR2, EGR3 or EGR4 terminal output voltage is excessively low, and the step motor is not operating, the ECM determines that there is an open in the EGR valve assembly circuit, and sets the DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
CONFIRMATION DRIVING PATTERN
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG) and turn the Techstream on [A].
- Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) DTC Check / Clear.
- Turn the power switch off and wait for 30 seconds.
- Turn the power switch on (IG) and turn the Techstream on.
- Put the engine in inspection mode Component Tests and General Diagnostics.
- Start the engine and warm it up [B].
- Drive the vehicle at 12 mph (20 km/h) or more for 10 minutes [C].
- Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [D].
- Read the DTC.
- If a DTC is output, the system is malfunctioning.
HINT
If a 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.
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform step [C] again.
- Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
- Check the judgment result.
HINT
If the judgment result shows ABNORMAL, the system has a malfunction.
- If the test result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.
HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
Read freeze frame data using an Techstream. 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
1. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Put the engine in inspection mode Component Tests and General Diagnostics.
(e) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or more.
HINT
The A/C switch and all accessory switches should be off.
(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.
(g) Confirm the Throttle Idle Position is ON and check the engine idling condition and MAP values 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 Active Test is completed.
OK:
MAP and idling condition change in response to EGR step position as follows.
Standard:
HINT
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.
Result:
B -- INSPECT EGR VALVE ASSEMBLY
A -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems
2. INSPECT EGR VALVE ASSEMBLY
(a) Disconnect the EGR valve assembly connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
(c) Reconnect the EGR valve assembly connector.
NG -- REPLACE EGR VALVE ASSEMBLY Removal
OK -- Continue to next step.
3. INSPECT EGR VALVE ASSEMBLY (+B1 OR +B2 VOLTAGE)
(a) Disconnect the EGR valve assembly connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
(d) Reconnect the EGR valve assembly connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (EGR VALVE ASSEMBLY - EFI MAIN RELAY)
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (ECM - EGR VALVE ASSEMBLY)
(a) Disconnect the EGR valve assembly connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
Text in Illustration
(d) Reconnect the EGR valve assembly connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - EGR VALVE ASSEMBLY)
OK -- REPLACE ECM Removal