Dtc P1605 Rough Idling

Engine Hybrid System. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
2Tr-Fbe Engine Control. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

INSPECTION PROCEDURE

CHECK FOR ANY OTHER DTCS OUTPUT

CHECK FREEZE FRAME DATA

DTC P1605 Rough Idling


DESCRIPTION

If the engine speed becomes lower than a predetermined level, this DTC will be stored.
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
It is necessary to check if the vehicle has run out of fuel before starting diagnosis because this DTC is also stored due to running out of fuel.

DTC No.
DTC Detection Condition
Trouble Area
P1605
After 5 seconds or more elapse after starting the engine, with the engine running, the engine speed drops to 400 rpm or less
(1 trip detection logic)
  1. Intake system connection
  2. Purge VSV
  3. Brake booster
  4. Mass air flow meter sub-assembly
  5. Engine coolant temperature sensor
  6. Wire harness or connector
  7. Air fuel ratio sensor (sensor 1)
  8. Power source circuit (purge VSV, fuel injector assembly, ignition coil assembly)
  9. Fuel pump (for fuel main tank)
  10. Fuel pump control circuit
  11. Fuel line
  12. Throttle body with motor assembly
  13. Camshaft timing oil control valve assembly
  14. Knock control sensor
  15. Ignition coil assembly
  16. Fuel injector assembly
  17. Spark plug
  18. Air conditioner system
  19. Power steering system
  20. Electrical load signal circuit
  21. A/T system
  22. Park/neutral position switch circuit
  23. Sub tank fuel pump control circuit
  24. Fuel pump (for fuel sub tank)
  25. Fuel jet
  26. Solenoid valve assembly (for fuel injection volume control)
  27. Solenoid valve assembly (for fuel cut control)
  28. ECM

INSPECTION PROCEDURE

HINT:
  1. In contrast to normal malfunction diagnosis for components, circuit and systems, DTC P1605 is used to determine the malfunctioning area from the problem symptoms and freeze frame data when the user mentions problems such as engine stall.
    As this DTC can be stored as a result of certain user actions, even if this DTC is output, if the customer makes no mention of problems, clear this DTC without performing any troubleshooting and return the vehicle to the customer.
  2. If any DTCs other than P1605 are output, troubleshoot those DTCs first.
  3. Since DTC P1605 is different from other DTCs, the following procedure is shown as a reference.
  4. Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
1.CHECK FOR ANY OTHER DTCS OUTPUT

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

  1. Read the DTCs.

    Result:

    Result
    		Proceed to
    DTC P1605 is output
    		A
    DTC 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 RM000000PDF0H4X.html)
A


2.CHECK FREEZE FRAME DATA

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

  1. Check the following freeze frame data to see if the engine was cold or warm when the freeze frame data was recorded.

    Confirmation Item
    Coolant Temp
    Initial Engine Coolant Temp
    Initial Intake Air Temp
    Engine Run Time

  1. Check the following freeze frame data recorded when the engine was idling.

    Confirmation Item
    Engine Speed
    Closed Throttle Position SW
    Neutral Position SW Signal

  1. Check the following freeze frame data to see the purge VSV operation status when the freeze frame data was recorded.

    Confirmation Item
    EVAP (Purge) VSV
    Evap Purge Flow
    Purge Density Learn Value
    EVAP Purge VSV

  1. Check the following freeze frame data to see information related to engine idling from when the freeze frame data was recorded.

    Confirmation Item
    Shift SW Status (P Range)
    Shift SW Status (N Range)
    Shift SW Status (D Range)

  1. Check the following freeze frame data to see the engine load and electrical load when the freeze frame data was recorded.

    Confirmation Item
    Calculate Load
    Electrical Load Signal
    A/C Signal
    Power Steering Signal
    Electric Fan Motor

  1. Check the following freeze frame data to see the air fuel ratio recorded when the idle speed was not stable.

    Confirmation Item
    Short FT #1
    Long FT #1
    AF Lambda B1S1

  1. Check the following freeze frame data to see the ignition timing recorded when the idle speed was not stable.

    Confirmation Item
    IGN Advance
    Knock Correct Learn Value

  1. Check the following freeze frame data to see the FFV (Flexible Fuel Vehicle) information recorded when the idle speed was not stable.

    Confirmation Item
    Alcohol Feedback Value
    Alc FB Val bfr F/Crrctn by Stall
    Trip aft F/Crrctn by Stall
    Fuel Dilution Estimate

  1. Use this information to perform a simulation test.

  1. Compare the "Normal Condition" in the Data List (reference values) with the freeze frame data listed above and with the simulation test results to determine the problem cause.

    Result:

    Result
    		Proceed to
    The problem cause can be determined
    		A
    The problem cause cannot be determined
    		B


B
CHECK FOR INTERMITTENT PROBLEMS (HILUX_TGN26 RM000000PDQ0YMX.html)
A

REPAIR OR REPLACE MALFUNCTIONING PARTS