ECD SYSTEM (w/o DPF), Diagnostic DTC:P1605

DTC Code DTC Name
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.

P1605
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
- The engine speed drops to less than 400 rpm (1 trip detection logic).

  • Injector assembly

  • Injector compensation code

  • Fuel leak

  • Glow system

  • Intake air system leakage

  • Intake air system blockage

  • EGR system

  • Throttle valve system

  • Suction control valve

  • Low quality fuel

  • Fuel filter element sub-assembly air bleed problem

  • Accessory problem (A/C, generator, etc.)

  • Engine assembly

  • ECM
Related Data List
DTC No. Data List
P1605

  • Engine Speed

  • MAP

  • MAF

  • Coolant Temp

  • Battery Voltage

  • Engine Speed of Cyl #1 (to #4)

  • Intake Air

  • Target Common Rail Pressure

  • Fuel Press

  • Target Pump SCV Current

  • Injection Feedback Val #1 (to #4)

  • Injection Volume

  • Actual Throttle Position

  • Target EGR Position

  • Actual EGR Valve Pos.

  • EGR Close Lrn. Status

  • EGR Close Lrn. Val.

  • After Glow

INSPECTION PROCEDURE


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

  2. 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.

  3. Fuel system


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


      1. Fuel leakage.

      2. Problem with injector assemblies.

      3. Problem with fuel supply pump assembly.

      4. Air in fuel pipe.

  4. Engine assembly


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


      1. Insufficient compression.

    Tech Tips


    • In contrast to normal malfunction diagnosis for components, circuits and systems, DTCs P1603 and P1605 are used to determine the malfunctioning area from the problem symptoms and freeze frame data when the user mentions problems such as engine stall.

      As these DTCs can be stored as a result of certain user actions, even if these DTCs are output, if the customer makes no mention of problems, clear these DTCs without performing any troubleshooting and return the vehicle to the customer.

    • If any other DTCs are output, perform troubleshooting for those DTCs first.

    • 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.

    • When confirming the freeze frame data, be sure to check all 5 sets of freeze frame data.

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

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

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

    4. Read the DTCs.

      Result
      Result Proceed to
      P1605 A
      P1605 and other DTCs B

      Tech Tips

      If any DTCs other than P1605 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

    GO TO ROUGH IDLING OR EXCESSIVE ENGINE VIBRATIONS Click here