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SFI SYSTEM, Diagnostic DTC:P1604

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DTC Code DTC Name
P1604 Startability Malfunction
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DESCRIPTION

If the engine does not start or it takes a long time for the engine to start although the STA signal is input to the ECM, 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 help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

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
P1604

Either of the conditions is met (1trip detection logic):


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

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

  • Immobiliser system

  • Engine unit (excessive friction, decreased compression)

  • Starter system

  • Crankshaft position sensor circuit

  • Engine coolant temperature sensor circuit

  • Fuel pump

  • Fuel pump control circuit

  • Fuel line

  • Fuel injector assembly circuit

  • Throttle position sensor (built into throttle with motor body assembly)

  • Pressure regulator

  • Battery

  • Drive plate

  • Spark plug

  • Ignition coil assembly circuit

  • Intake system connection

  • Camshaft timing oil control valve assembly

  • Mass air flow meter sub-assembly

  • Air fuel ratio sensor (sensor 1)

  • Heated oxygen sensor (sensor 2)

  • Valve timing

  • Camshaft position sensor

  • Crankshaft position sensor

  • Fuel

  • Purge VSV

  • Intake valve

  • ECM
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INSPECTION PROCEDURE

Tip:

  • 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 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 DTCs other than P1604 are output, troubleshoot those DTCs first.

  • Since DTC P1604 is different from other DTCs, the following procedure is shown as a reference.

  • 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 running or stopped, 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.

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PROCEDURE


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    CHECK IF ENGINE CRANKS


    1. Check if the engine cranks.

      Result
      Result Proceed to
      The engine cranks A
      The engine does not crank B

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    CHECK ANY OTHER DTCS OUTPUT


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

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

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P1604 is output A
      DTC P1604 and other DTCs are output B
      Tip:

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


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    CHECK FREEZE FRAME DATA


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Check the following freeze frame data to see the state of the battery when the freeze frame data was recorded.

      Table 1. Confirmation Item
      Battery Voltage

    5. Check the following freeze frame data to see if the engine was cranking when the freeze frame data was recorded.

      Table 2. Confirmation Item
      Engine Speed
      Fuel Pump/Speed Status

    6. Check the following freeze frame data to check temperature data recorded when the engine did not start normally.

      Table 3. Confirmation Item
      Coolant Temp
      Intake Air

    7. Check the following freeze frame data to see the engine operating conditions recorded when the engine started.

      Table 4. Confirmation Item
      MAF

    8. Check the following freeze frame data to see the air fuel ratio recorded when the engine started.

      Table 5. Confirmation Item
      Long FT #1

    9. Use this information to perform a simulation test.

    10. Compare the "Normal Condition" in the Data List table (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

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    REPAIR OR REPLACE MALFUNCTIONING PARTS

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    GO TO PROBLEM SYMPTOMS TABLEClick here

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    GO TO DTC CHARTClick here

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    CHECK FOR INTERMITTENT PROBLEMSClick here