SFI SYSTEM (w/ Dual VVT-i), Diagnostic DTC:P1604

DTC Code DTC Name
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 conditions is met:


  • The engine speed is below 500 rpm with the STA signal on for a certain amount of time (refer to the illustration below)

    (1 trip detection logic)

  • After the engine starts (engine speed is 500 rpm or more), the engine speed drops to 200 rpm or less within approximately 2 seconds

    (1 trip detection logic)

A003IB7E01
Trouble Area
Ignition system
  • Spark plug

  • Ignition coil assembly

Fuel system
  • Fuel injector assembly

  • Fuel pump

  • Fuel pump control circuit

  • Fuel pressure regulator assembly

  • Fuel line

  • Purge VSV system

  • Fuel quality (existence of foreign matter, degradation)

Intake and exhaust systems
  • Mass air flow meter sub-assembly

  • Intake system (Air leaks or deposit accumulation)

  • Throttle body assembly

  • Air fuel ratio sensor

  • Heated oxygen sensor

  • Camshaft timing oil control assembly

  • Variable Valve Timing system (VVT system)

  • Brake booster assembly

Other control systems
  • ECM

  • Wire harness or connector

  • Knock control sensor

  • Engine coolant temperature sensor

Engine
  • Thermostat

  • Engine assembly

  • Engine mount

High load from another system
  • Air conditioning system

  • Power steering system

  • Electrical load signal system

  • A/T system

INSPECTION PROCEDURE


PROCEDURE


  1. CHECK FOR ANY OTHER DTCS OUTPUT


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

    5. Read the DTCs.

      Result
      Result Proceed to
      Only DTC P1604 is output A
      DTCs other than P1604 are output B

      Tech Tips


      • If any DTCs other than P1604 is output, troubleshoot those DTCs first.

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


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Using the GTS, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored. Click here

      OK
      Data List Item GTS Display
      Immobiliser Communication ON
      Immobiliser Fuel Cut OFF

      Tech Tips

      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.


    NG
    OK
  3. READ FREEZE FRAME DATA (ISC LEARNING VALUE)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Using the GTS, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored. Click here

      Result
      Freeze Frame Data Item for DTC P1604 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 higher Throttle valve assembly Go to Engine Difficult to Start (from step 15 (REMOVE FOREIGN OBJECT (CLEAN THROTTLE BODY ASSEMBLY)) B

    B
    A
  4. READ FREEZE FRAME DATA (ENGINE SPEED)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Using the GTS, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored. Click here

      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)
      • Starter signal circuit

      • Crankshaft position sensor system

      • Battery fully depleted

      Go to Engine Difficult to Start (from step 5 (CHECK CRANKING)) A
      100 to 500 rpm (engine cranked but initial combustion did not occur or was delayed)
      • Fuel pump

      • Leaking fuel injector assembly

      • Spark plug

      • 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)
      • Spark plug

      • Ignition coil assembly


    A
    B
  5. INTERVIEW THE CUSTOMER


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

      Tech Tips

      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 (INSPECT FUEL INJECTOR ASSEMBLY)) A
      Other than above
      • Fuel pump

      • Spark plug

      • Ignition coil assembly

      Go to the next step B

    A
    B
  6. INTERVIEW THE CUSTOMER


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

      Tech Tips

      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
      Mostly driven short distances
      • Spark plug

      • Ignition coil assembly

      Go to Engine Difficult to Start (from step 13 (CHECK IGNITION SYSTEM)) NEXT
      Not mostly driven short distances
      • Fuel pump

      • Spark plug

      • Ignition coil assembly

      Go to Engine Difficult to Start (from step 9 (READ VALUE USING GTS (SHORT FT AND LONG FT))

    NEXT