DESCRIPTION
Refer to DTC P0401 Click here.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0403 | Open or short in EGR valve circuit (1 trip detection logic). |
|
Tech Tips
DTC P0403 is stored 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 stores 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 stores the DTC.
MONITOR STRATEGY
| Related DTCs | P0403: EGR valve circuit range check |
| Required Sensors/Components (Main) | EGR valve assembly |
| Required Sensors/Components (Related) | - |
| Frequency of Operation | Continuous |
| Duration | - |
| MIL Operation | Immediate |
| Sequence of Operation | None |
TYPICAL ENABLING CONDITIONS
| Monitor runs whenever the following DTCs are not stored | None |
| All of the following conditions are met | - |
| Engine | Running |
| Auxiliary battery voltage | 10.5 V or higher |
| Time after power switch off to on (IG) | 0.5 seconds or more |
TYPICAL MALFUNCTION THRESHOLDS
| One of the following conditions is met | Condition A, B, C or D |
| A. All of the following conditions are met | - |
| EGR1 output terminal voltage | Low |
| Either of the following conditions is met | Condition 1 or 2 |
| 1. Step motor | Driving |
| 2. EGR1 | Not operating |
| B. All of the following conditions are met | - |
| EGR2 output terminal voltage | Low |
| Either of the following conditions is met | Condition 3 or 4 |
| 3. Step motor | Driving |
| 4. EGR2 | Not operating |
| C. All of the following conditions are met | - |
| EGR3 output terminal voltage | Low |
| Either of the following conditions is met | Condition 5 or 6 |
| 5. Step motor | Driving |
| 6. EGR3 | Not operating |
| D. All of the following conditions are met | - |
| EGR4 output terminal voltage | Low |
| Either of the following conditions is met | Condition 7 or 8 |
| 7. Step motor | Driving |
| 8. EGR4 | Not operating |
CONFIRMATION DRIVING PATTERN
Connect the Techstream to the DLC3.
Turn the power switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG) and turn the Techstream on [A].
Put the engine in inspection mode (maintenance mode) Click here.
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.
Tech Tips
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.
| Techstream Display | Description |
|---|---|
| NORMAL |
|
| ABNORMAL |
|
| INCOMPLETE |
|
| N/A |
|
Tech Tips
If the judgment result shows NORMAL, the system has a normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs Click here.
Tech Tips
If a permanent DTC is output, the system is malfunctioning.
If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
INSPECTION PROCEDURE
Note
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
Tech Tips
Read freeze frame data using the 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
PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION)
Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.
Put the engine in inspection mode (maintenance mode) Click here.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tech Tips
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 / Primary / Throttle Idle Position and MAP.
Confirm that the Throttle Idle Position is ON and check the MAP value in the Data List while performing the Active Test.
Tech Tips
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.
| OK |
|---|
| MAP change in response to EGR step position when Throttle Idle Position is ON in Data List. |
| Standard | ||||||||
|---|---|---|---|---|---|---|---|---|
|
||||||||
Tech Tips
While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.
| NG |
|
INSPECT EGR VALVE ASSEMBLY Click here |
| OK |
|
CHECK FOR INTERMITTENT PROBLEMS Click here
INSPECT EGR VALVE ASSEMBLY
Inspect the EGR valve assembly Click here.
Tech Tips
Perform "Inspection After Repair" after replacing the EGR valve assembly Click here.
| NG |
|
REPLACE EGR VALVE ASSEMBLY Click here |
| 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 power switch on (IG).
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
CHECK HARNESS AND CONNECTOR (EGR VALVE ASSEMBLY - NO. 1 INTEGRATION RELAY) Click here |
| 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 | |||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
REPLACE ECM Click here
CHECK HARNESS AND CONNECTOR (EGR VALVE ASSEMBLY - NO. 1 INTEGRATION RELAY)
Disconnect the EGR valve assembly connector.
Remove the No. 1 integration relay from the engine room relay block and junction block assembly.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
REPLACE NO. 1 INTEGRATION RELAY Click here