Dtc P1604 Startability Malfunction


DESCRIPTION

INSPECTION PROCEDURE

CHECK FOR ANY OTHER DTCS OUTPUT

READ FREEZE FRAME DATA (IMMOBILISER COMMUNICATION AND IMMOBILISER FUEL CUT)

READ FREEZE FRAME DATA (ISC LEARNING VALUE)

READ FREEZE FRAME DATA (ENGINE SPEED)

INTERVIEW THE CUSTOMER

INTERVIEW THE CUSTOMER

DTC P1604 Startability Malfunction


DESCRIPTION

This DTC is stored when the engine does not start even though the STA signal is input or when the engine takes a long time to start, and when the engine speed is low or the engine stalls just after the engine starts.
Using the GTS, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.
It is necessary to check if the vehicle ran out of fuel before performing troubleshooting, as this DTC is also stored when there is engine starting trouble due to running out of fuel.

DTC No.
DTC Detection Condition
P1604
Either condition is met (1 trip detection logic):
  1. The engine speed is below 500 rpm with the STA signal on for a certain amount of time (refer to the illustration below).
  2. After the engine starts (engine speed is 500 rpm or more), the engine speed drops to 200 rpm or less within approximately 2 seconds.

Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.2Tr-Fe Engine Control.Sfi System. Dtc P1604 Startability Malfunction


Trouble Area
Ignition system
  1. Spark plug
  2. Ignition coil assembly
Fuel system
  1. Fuel injector assembly
  2. Fuel pump
  3. Fuel pump control circuit
  4. Fuel pressure regulator assembly
  5. Fuel line
  6. Purge VSV system
  7. Fuel quality (existence of foreign matter, degradation)
Intake and exhaust systems
  1. Mass air flow meter sub-assembly
  2. Intake system (Air leaks or deposit accumulation)
  3. Throttle body with motor assembly
  4. Air fuel ratio sensor
  5. Heated oxygen sensor
  6. Camshaft timing oil control assembly
  7. Variable Valve Timing system (VVT system)
  8. Brake booster assembly
Other control systems
  1. ECM
  2. Wire harness or connector
  3. Knock sensor
  4. Engine coolant temperature sensor
Engine
  1. Thermostat
  2. Engine assembly
  3. Engine mount
High load from another system
  1. Air conditioning system
  2. Power steering system
  3. Electrical load signal system
  4. AT system

INSPECTION PROCEDURE

  1. In contrast to normal malfunction diagnosis for components, circuits and systems, DTC P1604 is used to determine the malfunctioning area from the problem symptoms and freeze frame data when the user mentions problems such as starting difficulty.
    As this DTC can be stored as a result of certain user actions, even if the DTC is output, if the customer makes no mention of problems, clear the DTC 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. When this Data List item "Immobiliser Fuel Cut" is ON, the engine cannot be started.
  4. Read freeze frame data using the GTS. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.
  5. When confirming the freeze frame data, be sure to check all 5 sets of freeze frame data (LandCruiser RM000000SXU01JX.html).
  6. When confirming the freeze frame data, if there are multiple items related to the cause of the malfunction, perform troubleshooting for all related items.
  7. Try to start the vehicle under the conditions recorded in the freeze frame data which were present when the malfunction occurred. Confirm the data at this time and compare it with the freeze frame data.
  8. If the malfunction does not recur, carefully check the vehicle conditions from when the malfunction occurred using freeze frame data.
  9. When performing inspections, jiggle the relevant wire harnesses and connectors in an attempt to reproduce malfunctions that do not always occur.
  10. If the same inspection or replacement procedure appears 2 times when performing an inspection procedure, it is not necessary to repeat the procedure the second time.
1.CHECK FOR ANY OTHER DTCS OUTPUT

  1. Connect the GTS to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the GTS on.

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

  1. Read the DTCs.

    Result:

    Result
    		Proceed to
    DTC P1604 is output
    		A
    DTC P1604 and other DTCs are output
    		B
    HINT:
    1. If any DTCs other than P1604 are output, troubleshoot those DTCs first.
    2. Using freeze frame data, confirm the conditions the moment the DTC was stored and after the DTC was stored. This information can be useful when troubleshooting.


B
GO TO DTC CHART (LandCruiser RM000000VNN00FX.html)
A


2.READ FREEZE FRAME DATA (IMMOBILISER COMMUNICATION AND IMMOBILISER FUEL CUT)

  1. Connect the GTS to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the GTS on.

  1. Using the GTS, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored (LandCruiser RM000000SXU01JX.html).

    OK:

    Data List Item
    		GTS Display
    Immobiliser Communication
    		ON
    Immobiliser Fuel Cut
    		OFF
    HINT:
    If the engine is started immediately after reconnecting the battery terminal, the engine may stall immediately after it starts due to the intercommunication process between each ECU. For this reason, when starting the engine after reconnecting the battery terminal, first turn the ignition switch to ON and then wait several seconds for the communication process to complete before starting the engine.

    Result:

    Result
    		Proceed to
    OK
    		A
    NG (w/ Entry and Start System)
    		B
    NG (w/o Entry and Start System)
    		C


B
CHECK IMMOBILISER SYSTEM (LandCruiser RM000000QY40G3X.html)

C
CHECK IMMOBILISER SYSTEM (LandCruiser RM000001GUQ05EX.html)
A


3.READ FREEZE FRAME DATA (ISC LEARNING VALUE)

  1. Connect the GTS to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the GTS on.

  1. Using the GTS, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored (LandCruiser RM000000SXU01JX.html).

    Result:

    Freeze Frame Data Item
    		Result
    		Suspected Area
    		Action
    		Proceed to
    ISC Learning Value
    		Less than 6.2 L/s
    		-
    		Go to the next step
    		A
    6.2 L/s or more
    		Throttle valve assembly
    		Go to Engine Difficult to Start (from step 15)
    		B


B
GO TO ENGINE DIFFICULT TO START (LandCruiser RM000005RMD019X.html)
A


4.READ FREEZE FRAME DATA (ENGINE SPEED)

  1. Connect the GTS to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the GTS on.

  1. Using the GTS, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored (LandCruiser RM000000SXU01JX.html).

    Result:

    Freeze Frame Data Item
    		Result
    		Suspected Area
    		Action
    		Proceed to
    Engine Speed
    		All 5 sets of freeze frame data are 0 rpm (engine did not crank or engine speed was not detected properly)
    1. Starter signal circuit
    2. Crankshaft position sensor system
    3. Battery fully depleted
    		Go to Engine Difficult to Start (from step 5)
    		A
    100 to 500 rpm (engine cranked but initial combustion did not occur or was delayed)
    1. Fuel pump
    2. Leaking fuel injector assembly
    3. Spark plug
    4. Ignition coil assembly
    		Go to the next step
    		B
    500 rpm or higher (engine speed dropped immediately after initial combustion) (Low Rev for Eng Start is ON)
    1. Spark plug
    2. Ignition coil assembly


B
Go to step 5
A

GO TO ENGINE DIFFICULT TO START (LandCruiser RM000005RMD019X.html)

5.INTERVIEW THE CUSTOMER

  1. Interview the customer for details about the conditions when the malfunction occurred.

    HINT:
    If the engine is difficult to start only when the vehicle has been left as is for a long time, a leaking fuel injector assembly is suspected.

    Result:

    Result
    		Suspected Area
    		Action
    		Proceed to
    Engine is difficult to start only when the vehicle has been left as is for a long time (1 hour or more)
    		Leaking fuel injector assembly
    		Go to Engine Difficult to Start (from step 4)
    		A
    Other than above
    1. Fuel pump
    2. Spark plug
    3. Ignition coil assembly
    		Go to the next step
    		B


B
Go to step 6
A

GO TO ENGINE DIFFICULT TO START (LandCruiser RM000005RMD019X.html)

6.INTERVIEW THE CUSTOMER

  1. Interview the customer for details about the conditions when the malfunction occurred.

    HINT:
    If the vehicle is mostly driven for short distances, deposits may have accumulated on the spark plugs, causing starting difficulty.

    Result:

    Result
    		Suspected Area
    		Action
    		Proceed to
    Mostly driven short distances
    1. Spark plug
    2. Ignition coil assembly
    		Go to Engine Difficult to Start (from step 13)
    		NEXT
    Not mostly driven short distances
    1. Fuel pump
    2. Spark plug
    3. Ignition coil assembly
    		Go to Engine Difficult to Start (from step 9)

NEXT

GO TO ENGINE DIFFICULT TO START (LandCruiser RM000005RMD019X.html)