| DTC Code | DTC Name |
|---|---|
| P0488 | Exhaust Gas Recirculation Throttle Position Control Range / Performance |
DESCRIPTION
The ECM opens and closes the throttle valve using a DC motor type actuator. Due to the opening and closing of the valve, the exhaust gas recirculation volume can be properly controlled. Also, engine vibration and noise will be reduced by closing the valve when the engine is stopped.
Although the DTC title says "Exhaust Gas Recirculation Throttle Position Control Range / Performance", this DTC indicates that the throttle valve is malfunctioning.
| DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
|---|---|---|
| Perform the following repeatedly for 1 minute: gradually raise the engine speed to 3000 rpm from idling over approximately 10 seconds, and then release the accelerator pedal to return to an idling state. | The throttle actuator activation duty is more than specified value for 30 seconds. (1 trip detection logic) |
|
| DTC No. | Data List |
|---|---|
| P0488 |
|
| Condition | Throttle Valve Position |
|---|---|
| Moment when accelerator pedal is depressed further or released at 3000 rpm | Throttle valve opening angle varies smoothly |
MONITOR DESCRIPTION
The ECM opens and closes the throttle valve by adjusting the current flowing to the DC motor with a duty ratio. If the throttle valve does not move smoothly or is stuck, the duty ratio used during valve movement control increases or decreases greatly. The ECM will determine that the throttle valve is malfunctioning and illuminate the MIL.
WIRING DIAGRAM
Refer to DTC P0122 Click here.
INSPECTION PROCEDURE
Note
When cleaning the diesel throttle body assembly, use a piece of cloth soaked with cleaning solvent. Spraying solvent directly onto these parts or soaking the parts in solvent may damage the parts.
After replacing the ECM, the new ECM needs registration Click here and initialization Click here.
Tech Tips
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, and other data from the time the malfunction occurred.
PROCEDURE
PERFORM ACTIVE TEST USING GTS (DIESEL THROTTLE TARGET ANGLE)
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Diesel Throttle Target Angle / Data List / Primary / Actual Throttle Position.
When changing the Active Test continuously value to 10, 30, 60, 90, 60, 30 and 10%, check that Actual Throttle Position smoothly changes to the set opening angle.
| OK |
|---|
| Value smoothly changes to set opening angle. |
| NG |
|
REMOVE DEPOSIT (DIESEL THROTTLE BODY ASSEMBLY) Click here |
| OK |
|
REMOVE DEPOSIT (DIESEL THROTTLE BODY ASSEMBLY)
Visually check for deposits in the diesel throttle body assembly. If there are deposits, clean the diesel throttle body assembly.
Note
When cleaning the diesel throttle body assembly, use a piece of cloth soaked with cleaning solvent. Spraying solvent directly onto these parts or soaking the parts in solvent may damage the parts.
Extreme care must be taken to prevent the removed deposits from falling into the engine unit during cleaning.
| NEXT |
|
INSPECT DIESEL THROTTLE BODY ASSEMBLY (THROTTLE VALVE MOVEMENT)
Using your finger, move the throttle valve from the fully open position to the fully closed position and check that it moves smoothly.
| OK |
|---|
| Throttle valve moves smoothly. |
Note
Take care not to damage the throttle valve or valve housing.
| NG |
|
REPLACE DIESEL THROTTLE BODY ASSEMBLY Click here |
| OK |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P0488)
Start the engine and warm it up.
Connect the GTS to the DLC3.
Turn the GTS on.
Take a snapshot with the GTS.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Diesel Throttle Target Angle / Data List / Primary / Actual Throttle Position.
Tech Tips
The movement of the throttle valve can be determined by performing the following inspection.
When changing the Active Test value continuously to 10, 30, 60, 90, 60, 30 and 10%, check that Actual Throttle Position smoothly changes to the set opening angle.
| OK |
|---|
| Value smoothly changes to set opening angle. |
Perform the following repeatedly for 1 minute: gradually raise the engine speed to 3000 rpm from an idling over approximately 10 seconds, and then release the accelerator pedal to return to an idling state.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs.
| OK |
|---|
| DTC is not output. |
| NG |
|
REPLACE ECM Click here |
| OK |
|
END
REMOVE DEPOSIT (DIESEL THROTTLE BODY ASSEMBLY)
Visually check for deposits in the diesel throttle body assembly. If there are deposits, clean the diesel throttle body assembly.
Note
When cleaning the diesel throttle body assembly, use a piece of cloth soaked with cleaning solvent. Spraying solvent directly onto these parts or soaking the parts in solvent may damage the parts.
Extreme care must be taken to prevent the removed deposits from falling into the engine unit during cleaning.
| NEXT |
|
INSPECT DIESEL THROTTLE BODY ASSEMBLY (THROTTLE VALVE MOVEMENT)
Using your finger, move the throttle valve from the fully open position to the fully closed position and check that it moves smoothly.
| OK |
|---|
| Throttle valve moves smoothly. |
Note
Take care not to damage the throttle valve or valve housing.
| NG |
|
REPLACE DIESEL THROTTLE BODY ASSEMBLY Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (DIESEL THROTTLE BODY ASSEMBLY - ECM)
Disconnect the diesel throttle body assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Reconnect the throttle control motor connector.
Reconnect the ECM connector.
| OK |
|
REPLACE DIESEL THROTTLE BODY ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
Repair or replace the harness or connector.
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS Click here |
REPLACE DIESEL THROTTLE BODY ASSEMBLY
Replace the diesel throttle body assembly Click here.
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS Click here |
REPLACE ECM
Replace the ECM Click here.
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS
Start the engine and warm it up.
Turn the ignition switch to ON and turn the GTS on.
Take a snapshot with the GTS.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Diesel Throttle Target Angle / Data List / Primary / Actual Throttle Position.
Tech Tips
The movement of the throttle valve can be determined by performing the following inspection.
When changing the Active Test value continuously to 10, 30, 60, 90, 60, 30 and 10%, check that Actual Throttle Position smoothly changes to the set opening angle.
| OK |
|---|
| Value smoothly changes to set opening angle. |
Perform the following repeatedly for 1 minute: gradually raise the engine speed to 3000 rpm from an idling over approximately 10 seconds, and then release the accelerator pedal to return to an idling state.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Confirm that the DTC is not output.
| NEXT |
|
END