DTC    P0488    Exhaust Gas Recirculation Throttle Position Control Range / Performance

for Preparation Click here


DESCRIPTION

The ECM opens and closes the throttle valve using a DC motor type actuator. With the throttle 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.

HINT:
Although the DTC titles say Exhaust Gas Recirculation Throttle Position Control Range / Performance, these DTCs relate to the throttle valve.


P0488 
DTC Detection Drive Pattern
DTC Detection Condition
Trouble Area
With a warm engine, turn the ignition switch from ON to off and wait for one minute or more to perform the close learning operation.
Both of following conditions are met for 3 times in one driving cycle:
  1. DC motor duty is 80% or more for 0.5 seconds.
  2. 20 seconds elapsed after above condition
(1 trip detection logic.)
  1. Throttle valve stuck
  2. Throttle valve does not move smoothly
  3. Open or short in diesel throttle circuit
  4. ECM

Related Data List 
DTC No.
Data List
P0488
  1. Target Throttle Position
  2. Actual Throttle Position
  3. Throttle Motor DUTY

Reference 
Condition
Throttle Valve Position
Moment when accelerator pedal is depressed further or released between idling and 3000 rpm
Throttle valve opening angle varies smoothly

HINT:
  1. If DTC P0488 is stored, the following symptoms may appear:
    1. Poor acceleration
    2. Lack of power due to a fail-safe operation
    3. Combustion noise worsens

  2. If carbon deposits exist in the diesel throttle body assembly, the following parts possibly also have deposits inside: The EGR valve assembly, intake manifold, DPF catalyst, and other parts related to the exhaust gas.
    By removing the EGR valve assembly from the intake manifold, the carbon deposit condition between the EGR valve and intake manifold can be checked visually. When checking the EGR valve assembly, hold the EGR valve to a light and confirm that the valve contacts with the valve seat securely.


    A200350E01

  3. For vehicles with DPF catalyst:
    If the DPF catalyst has become clogged with PM (Particulate Matter) and the value of the "Catalyst Differential Press" is more than 0.4 at an engine speed of 4000 rpm, DTC P2463 (Diesel Particulate Filter Restriction - Soot Accumulation) may be present. If the value of the "Catalyst Differential Press" is about 0.4 or less at an engine speed of 4000 rpm, the catalyst is probably clogged with PM even if DTC P2463 is not present. Check the Catalyst Differential Press by entering the following menus on an intelligent tester: Powertrain / Engine and ECT / Data List / Catalyst Differential Press.
    If the DPF catalyst has become clogged with PM (Particulate Matter) and the value of the "DPF Differential Pressure" is more than 80 kPa, DTC P2444B (Diesel Particulate Filter Differential Pressure Too High) may be present. If the value of the "DPF Differential Pressure" is more than 80 kPa, the catalyst is probably clogged with PM even if DTC P2444B is not present. Check the DPF Differential Pressure by entering the following menus on an intelligent tester: Powertrain / Engine and ECT / Data List / DPF Differential Pressure.


MONITOR DESCRIPTION

  1. Diesel throttle valve malfunction
    When the target and actual positions of the throttle valve are different for 60 seconds or more, the ECM interprets this as a malfunction of the throttle valve and illuminates the MIL

    A200362E02


WIRING DIAGRAM

Refer to DTC P0405 (Click here).

INSPECTION PROCEDURE

NOTICE:
  1. When cleaning the EGR valve or the diesel throttle body, use a piece of cloth. Spraying the solvent directly onto these parts or soaking the parts in the solvent may damage the parts.
  2. When replacing the ECM, the ECM needs Registration and Initialization (Click here).

HINT:
  1. When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the intelligent tester. Then after installing the new ECM, perform all of the initializations/registrations for the "Learning Values Write" function by following the instructions shown on the tester display.
  2. Read freeze frame data using the intelligent tester. 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.

1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0488)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Read the DTCs.
    Result 
    Result
    		Proceed to
    DTC P0488
    		A
    DTC P0488 and P2100, P2101, P2102 and/or P2103
    		B

    HINT:
    If any DTC P2100, P2101, P2102 and/or P2103 other than DTC P0488 are output, troubleshoot those DTCs first.



B
GO TO DTC CHART (Click here)
A


2.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (DIESEL THROTTLE TARGET ANGLE)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Enter the following menus: Powertrain / Engine and ECT / Active Test / Diesel Throttle Target Angle.

  1. When changing continuously the Active Test value at 0, 30, 60, 90, 60, 30 to 0%, check that Actual Throttle Position smoothly changes to the set opening angle.

    OK:
    Value smoothly changes to the set opening angle.



NG
Go to step 7
OK


3.INSPECT VACUUM HOSE AND PIPE (BETWEEN INTERCOOLER AND INTAKE MANIFOLD)

  1. Check for water or water marks in the hoses and pipes between the intercooler and intake manifold.

    OK:
    No water or water marks in the hoses and pipes.

    HINT:
    If water or water marks exist, water may have frozen in the diesel throttle body. The DTC was possibly caused by the presence of ice.

  1. Inspect the hoses and pipes between the intercooler and intake manifold.

    OK:
    Hoses and pipes are not damaged, squashed, or disconnected.



OK
Go to step 5

NG
Go to step 4

4.REPAIR OR REPLACE VACUUM HOSE AND PIPE

  1. Repair or replace the vacuum hoses or pipes.


NEXT


5.CHECK FOR DEPOSIT (DIESEL THROTTLE BODY ASSEMBLY)

  1. Check for any deposits in the diesel throttle body assembly.

    OK:
    No deposits in the diesel throttle body assembly.

    HINT:
    If carbon deposits exist in the diesel throttle body assembly, the following parts possibly also have deposits inside: The EGR valve assembly, intake manifold, DPF catalyst, and other parts related to the exhaust gas. By removing the EGR valve assembly from the intake manifold, the carbon deposit condition between the EGR valve and intake manifold can be checked visually. When checking for deposits in the EGR valve assembly, hold the EGR valve to a light and confirm that the valve contacts with the valve seat securely.

  1. If there is the deposits, remove it from the throttle body assembly and clean it.

    NOTICE:
    When cleaning the EGR valve or the diesel throttle body, use a piece of cloth. Spraying the solvent directly onto these parts or soaking the parts in the solvent may damage the parts.


A200353E01


NEXT


6.INSPECT DIESEL THROTTLE BODY ASSEMBLY (THROTTLE VALVE MOVEMENT)

  1. Using your finger, check that the throttle valve moves smoothly.

    OK:
    Throttle valve moves smoothly.

    NOTICE:
    Take care that you do not damage the throttle valve and the valve housing.



OK
Go to step 12

NG
Go to step 11

7.CHECK FOR DEPOSIT (DIESEL THROTTLE BODY ASSEMBLY)

  1. Check for any deposits in the diesel throttle body assembly.

    OK:
    No deposits in the diesel throttle body assembly.

    HINT:
    If carbon deposits exist in the diesel throttle body assembly, the following parts possibly also have deposits inside: The EGR valve assembly, intake manifold, DPF catalyst, and other parts related to the exhaust gas. By removing the EGR valve assembly from the intake manifold, the carbon deposit condition between the EGR valve and intake manifold can be checked visually. When checking for deposits in the EGR valve assembly, hold the EGR valve to a light and confirm that the valve contacts with the valve seat securely.

  1. If there is the deposits, remove it from the throttle body assembly and clean it.

    NOTICE:
    When cleaning the EGR valve or the diesel throttle body, use a piece of cloth. Spraying the solvent directly onto these parts or soaking the parts in the solvent may damage the parts.


A200353E01


NEXT


8.INSPECT DIESEL THROTTLE BODY ASSEMBLY (THROTTLE VALVE MOVEMENT)

  1. Using your finger, check that the throttle valve moves smoothly.

    OK:
    Throttle valve moves smoothly.

    NOTICE:
    Take care that you do not damage the throttle valve and the valve housing.



NG
Go to step 11
OK


9.CHECK HARNESS AND CONNECTOR (DIESEL THROTTLE BODY - ECM)


    A199035E03

  1. Disconnect the diesel throttle body assembly connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    B37-2 (M+) - A19-43 (M+)
    		Always
    		Below 1 Ω
    B37-1 (M-) - A19-42 (M-)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    B37-2 (M+) or A19-43 (M+) - Body ground
    		Always
    		10 kΩ or higher
    B37-1 (M-) or A19-42 (M-) - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Diesel Throttle Body Assembly)
    *2
    		Front view of wire harness connector
    (to ECM)

  1. Reconnect the diesel throttle body assembly connector.

  1. Reconnect the ECM connector.



OK
Go to step 11

NG
Go to step 10

10.REPAIR OR REPLACE HARNESS OR CONNECTOR


NEXT
Go to step 12

11.REPLACE DIESEL THROTTLE BODY ASSEMBLY

  1. Replace the diesel throttle body assembly (Click here).


NEXT


12.CHECK WHETHER DTC OUTPUT RECURS

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Clear DTCs (Click here).

  1. Turn the ignition switch off and wait for 1 minute or more.

  1. Turn the ignition switch to ON.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Read the DTCs.
    Result 
    Result
    		Proceed to
    DTC P0488
    		A
    No DTC output
    		B



B
END
A


13.REPLACE ECM

  1. Replace the ECM (Click here).


NEXT


14.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Clear DTCs (Click here).

  1. Turn the ignition switch off and wait for 1 minute or more.

  1. Turn the ignition switch to ON.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Confirm that the DTC is not output again.


NEXT

END