Dtc P1605 Rough Idling

Engine Hybrid System. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
1Kd-Ftv Engine Control. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

INSPECTION PROCEDURE

DTC OUTPUT (RECORD STORED DTC AND FREEZE FRAME DATA (PROCEDURE 1))

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

DETERMINE CAUSE OF PROBLEM (CHECK FREEZE FRAME DATA)

DTC P1605 Rough Idling


DESCRIPTION

This DTC is stored when the speed of a specific cylinder becomes low and the idle speed becomes unstable. 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
-
When the accelerator pedal is fully closed and the engine is idling, the speed of a specific cylinder is low for 2 to 10 seconds (1 trip detection logic).
  1. Injector assembly
  2. 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. Suction control valve
  10. Low quality fuel
  11. Fuel filter element sub-assembly air bleed problem
  12. Accessory problem (A/C, generator, etc.)
  13. Engine assembly
  14. ECM

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

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 control unit malfunction.


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.


Engine assembly

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

    1. Insufficient compression.

HINT:
  1. 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.
  2. If any other DTCs are output, perform troubleshooting for those DTCs first.
  3. 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.
  4. When confirming the freeze frame data, be sure to check all 5 sets of freeze frame data.
1.DTC OUTPUT (RECORD STORED DTC AND FREEZE FRAME DATA (PROCEDURE 1))

  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. Record the stored DTC and freeze frame data.

    HINT:
    This freeze frame data shows the actual engine conditions when air fuel ratio too rich trouble occurred.

NEXT


2.CHECK FOR 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
    		Proceed to
    P1605 is output
    		A
    P1605 and other DTCs are output
    		B

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


B
GO TO DTC CHART (HILUX_TGN26 RM0000031HW04RX.html)
A


3.DETERMINE CAUSE OF PROBLEM (CHECK FREEZE FRAME DATA)

  1. Determine the cause of the problem based on the freeze frame data recorded in Procedure 1.

    Rough Idle #1 to #4
    Judgment of Data List Values
    		Problem Cause
    		Diagnosis Note
    Any of Rough Idle #1 to #4 in the freeze frame data is ON
    		Injector assembly
    		If the cylinder that displays Rough Idle ON also has a value of more than 3.0 mm3/st for Injection Feedback Val, improper combustion in that cylinder is suspected.
    HINT:
    When there are temporary changes in the injection characteristics, the malfunction may not be indicated by the value for Injection Feedback Val in the freeze frame data.

    Injection Feedback Val #1(to #4)
    Judgment of Data List Values
    		Problem Cause
    		Diagnosis Note
    Any of Injection Feedback Val #1 to #4 in the freeze frame data is more than 3.0 mm3/st
    		Injector assembly
    		If the cylinder that displays Rough Idle ON also has a value of more than 3.0 mm3/st for Injection Feedback Val, improper combustion in that cylinder is suspected.


NEXT

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