Dtc P1605 Rough Idling


DESCRIPTION

INSPECTION PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1605)

DTC P1605 Rough Idling


DESCRIPTION

If the idle speed drops or becomes unstable when the engine is running at idle with a low load, this DTC is stored. This DTC is also stored if the vehicle runs out of fuel. Be sure to check whether there is enough fuel in the fuel tank before inspection.

DTC No.
DTC Detection Condition
Trouble Area
P1605
The engine speed drops below 400 rpm (1 trip detection logic).
  1. Fuel injector
  2. Fuel injector compensation code
  3. Fuel leak
  4. Glow system
  5. Intake air system leakage
  6. Intake air system blockage
  7. EGR system
  8. Throttle valve system
  9. Fuel supply pump
  10. Low quality fuel
  11. Fuel filter air bleed problem
  12. Accessory problem (A/C, generator, etc.)
  13. Engine assembly
  14. ECM

Related Data List
DTC No.
Data List
P1605
  1. Engine Speed
  2. MAP
  3. MAF
  4. Coolant Temp
  5. Battery Voltage
  6. Engine Speed of Cyl #1 (to #4)
  7. Intake Air
  8. Target Common Rail Pressure
  9. Fuel Press
  10. Target Pump SCV Current
  11. Injection Feedback Val #1 (to #4)
  12. Injection Volume
  13. Actual Throttle Position
  14. Target EGR Position
  15. Actual EGR Valve Pos.
  16. EGR Close Lrn. Status
  17. EGR Close Lrn. Val.
  18. After Glow

INSPECTION PROCEDURE


In order for idling to be stable, glow system operation, fuel system operation and compression sufficient to maintain the target idling speed are necessary.

Glow system

  1. The following malfunctions may be present in the glow system.

    1. Engine coolant temperature sensor malfunction.

    2. Glow plug malfunction.

    3. Glow relay malfunction.


Fuel system

  1. The following malfunctions may be present in the fuel system.

    1. Fuel leakage.

    2. Problem with injectors.

    3. Problem with supply pump.

    4. Air in fuel pipe.


Engine assembly

  1. The following malfunctions may be present in the engine assembly.

    1. Insufficient compression.

HINT:
  1. If any other DTCs are output, perform troubleshooting for those DTCs first.
  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.
  3. When confirming the freeze frame data, be sure to check all 5 sets of freeze frame data.
1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1605)

  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 (DTC Output)
    		Proceed to
    P1605
    		A
    P1605 and other DTCs
    		B
    HINT:
    If any DTCs other than P1605 are output, troubleshoot those DTCs first.


B
GO TO DTC CHART
A

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