ECD SYSTEM(w/ DPF), Diagnostic DTC:P1604

DTC Code DTC Name
P1604 Startability Malfunction

DESCRIPTION

This DTC is stored if the engine does not start or continues to crank without starting for a certain period of time. This DTC is also stored if the vehicle has run out of fuel. It is necessary to check whether there was enough fuel in the fuel tank before inspection.

P1604
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
During engine start (cranking)

During cranking engine cannot be started even after a maximum time of 30 seconds or engine cannot continue idling (engine stalls) for more than 2 seconds after cranking

(1 trip detection logic)

  • Battery

  • Starting system

  • Low quality fuel

  • Injector compensation code

  • Fuel filter

  • Cylinder compression pressure

  • Injector assembly

  • Engine coolant temperature sensor

  • Glow system

  • Supply pump assembly

  • Common rail assembly

  • ECM
Related Data List
DTC No. Data List
P1604

  • MAP

  • MAF

  • Intake Air

  • Coolant Temp

  • Battery Voltage

  • Starter Signal

  • Engine Speed of Cyl #1 (to #4)

  • Immobiliser Communication

  • Target Common Rail Pressure

  • Fuel Press

  • Target Pump SCV Current

  • Injection Feedback Val #1 (to #4)

  • Injection Volume

  • Actual Throttle Position

  • Throttle Motor Duty

  • Target EGR Pos.

  • Actual EGR Valve Pos.

  • EGR Close Lrn. Status

  • EGR Close Lrn. Val.

  • Pre Glow

  • After Glow

CAUTION / NOTICE / HINT

Tech Tips


  • 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.

  • 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.

  • When confirming the freeze frame data, be sure to check all 5 data sets of freeze frame data.

  • A01VJLAE46
    *a DTC is stored
    *b 0.5 seconds
    *c Freeze frame data recorded point

    The fourth set of freeze frame data is the data recorded when then the DTC is stored.


  1. In order to start the engine, the starting system, glow system, fuel system and the components related to compression must be functioning properly.

  2. The cause of the problem can be narrowed down by checking if the engine cranks normally.

  3. Starting system (when cranking is abnormal)


    1. The engine cannot be started if a sufficient cranking speed cannot be obtained. The following are possible causes of an insufficient cranking speed.


      1. Problem with the starting system (Engine does not crank).

      2. Problem with the immobiliser system (Engine does not crank).

      3. Problem with the battery (Cranking speed is low).

      4. Problem with the starter assembly (Cranking speed is low).

  4. Glow system (when cranking is normal)


    1. When there is a problem with the glow system, the intake air temperature does not rise adequately and the fuel combustion temperature is not reached. Therefore, there is no initial combustion or it takes time for the engine to start. The following are possible causes.


      1. Engine coolant temperature sensor malfunction.

      2. Glow plug malfunction.

        Tech Tips

        If the glow plug has deteriorated, the engine may be less likely to start when the outside temperature is lower than 0°C (32°F).

      3. Glow relay malfunction.

  5. Fuel system (when cranking is normal)


    1. The engine cannot be started if fuel is not supplied. A minimum fuel pressure of 25000 kPa or higher must be supplied to start the engine. The following are possible causes of insufficient fuel pressure.


      1. Fuel line clog.

      2. Lack of fuel.

      3. Fuel frozen.

      4. Low quality fuel.

      5. Air in fuel line.

      6. Fuel filter clog.

      7. Problem with supply pump assembly.

      8. Problem with common rail assembly.

      9. Problem with injector assemblies.

    A01VLOEE09

    Tech Tips

    If the startability of the engine does not recover after air enters the fuel system due to a lack of fuel, etc., there may be a malfunction in the check valve between the fuel return pipe from the injector assembly.

  6. Engine assembly


    1. There may be a problem with the engine unit itself if there is no problem with cranking, the glow system or fuel system.


      1. Engine friction too high.

      2. Insufficient compression.

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

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

    4. Record the stored DTC and Freeze Frame Data.

      Tech Tips

      This freeze frame data shows the actual engine conditions when engine starting trouble occurred.


    NEXT

  2. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1604)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

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

    4. Read DTCs.

      Result
      Result Proceed to
      DTC P1604 A
      DTC P1604 and other DTCs B

      Tech Tips

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


    B

    GO TO DTC CHART Click here

    A

  3. TAKE SNAPSHOT DURING STARTING AND IDLING (PROCEDURE 3)


    1. A01VE2ME27
      Text in Illustration
      *1 Snapshot Button
      *a Reference

      Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data.

    4. Take a snapshot of the following Data List items using the intelligent tester during "ignition switch ON (5 seconds) → Starting → Idling (10 seconds)".


    NEXT

  4. DETERMINE CAUSE OF PROBLEM (CHECK FREEZE FRAME DATA AND SNAPSHOT)


    1. Determine the cause of the problem based on the freeze frame data recorded in Procedure 1 and the Data List values recorded when starting the engine in Procedure 3.

      Coolant Temp
      Judgment of Data List Values Problem Cause Normal Condition Diagnosis Note
      "Coolant Temp" in freeze frame data is less than 35°C (95°F) Engine starting trouble which occurred with cold engine -

      • The engine coolant temperature is 60 to 90°C (140 to 194°F) after warming up the engine.

      • Normally, "Coolant Temp" is the same as the outside air temperature after an overnight engine soak.

      • Engine starting trouble with a cold engine occurs when the engine coolant temperature sensor is malfunctioning.

      "Coolant Temp" in Data List is less than 35°C (95°F)

      Currently, no engine starting trouble (cranking time less than 4 seconds) after warming up engine ("Coolant Temp" is 60°C (140°F) or more)

      		 Engine starting trouble which only occurs with cold engine
      Engine Speed
      Judgment of Data List Values Problem Cause Normal Condition Diagnosis Note
      "Engine Speed" in freeze frame data is less than 90 rpm Engine starting trouble may have occurred because engine speed was too low

      • During cranking: 90 to 400 rpm

      • Idling with warm engine: 720 to 820 rpm

      • The battery may be fully depleted or the battery terminals may be loose.

      • The viscosity of the engine oil may be inappropriate (low viscosity oil is not used).
      "Engine Speed" in Data List is less than 90 rpm when cranking engine
      Battery Voltage
      Judgment of Data List Values Problem Cause Normal Condition Diagnosis Note
      "Battery Voltage" in freeze frame data is below 7 V Engine starting trouble may have occurred because battery is fully depleted During cranking: 7 V or higher The battery may be fully depleted or the battery terminals may be loose.
      "Battery Voltage" in Data List is below 7 V when cranking engine
      Fuel Press
      Judgment of Data List Values Problem Cause Normal Condition Diagnosis Note
      "Fuel Press" in freeze frame data is below 1000 kPa

      Problem supplying fuel to supply pump assembly (low pressure side)


      • Ran out of fuel, air in fuel, fuel frozen (in this case, values of "Fuel Temperature" and "Coolant Temp" in freeze frame data are low)

      • Fuel filter clog, fuel line clog (low pressure side) or fuel leak

      • Feed pump (in supply pump assembly) malfunctioning

      		 When in a stable condition such as when idling, the fuel pressure is within +/-10000 kPa of the target fuel pressure Disconnect the inlet hose from the supply pump assembly (low pressure side), operate the hand pump and check that fuel is being supplied.
      "Fuel Press" in Data List is below 1000 kPa 2 seconds after engine cranking is started
      "Fuel Press" in freeze frame data is below 20000 kPa

      Problem supplying fuel to supply pump assembly (low pressure side) or problem on high pressure side


      • Supply pump assembly (suction control valve operation malfunction)

      • Common rail assembly

      • Injector assembly (if glow plug is covered with fuel when removed, injector assembly of corresponding cylinder may be stuck open)

      • Fuel line clog (high pressure side), fuel leak

      		 When in stable condition such as when idling, fuel pressure is within +/-10000 kPa of target fuel pressure

      • For startup at least 20000 kPa of fuel pressure is needed (Take care there is a response lag when the pressure rises)

      • If "Fuel Press" is 15000 kPa or less, fuel injection control is stopped.
      After cranking is started, "Fuel Press" in Data List increases to 20000 kPa or more and then decreases to below 15000 kPa
      "Fuel Press" in freeze frame data or Data List changes within range of 40000 to 45000 kPa

      • Injector assembly (fuel injection problem caused by air in injector assembly)

      • Problem with injection system

      		 When in a stable condition such as when idling, the fuel pressure is within +/-10000 kPa of the target fuel pressure

      • If there is air in the injector assemblies for all cylinders, fuel cannot be injected.

      • If there is an injection system problem related to 2 or more cylinders, fuel delivery and injection control are stopped.

      • When the EDU circuit (built into ECM) has a malfunction, the ECM cannot perform diagnosis of malfunctions and DTCs are not stored as voltage is unstable during cranking. Also, an excess amount of fuel is supplied by the supply pump assembly and "Fuel Press" becomes larger than "Target Common Rail Pressure" as fuel injection cannot be performed even though a fuel injection signal is output due to a failure to detect malfunctions at engine start.
      Target Pump SCV Current
      Judgment of Data List Values Problem Cause Normal Condition Diagnosis Note
      "Target Pump SCV Current" in freeze frame data is more than 1530 mA.

      • Supply pump assembly (SCV operation malfunction)

      • Fuel line clog

      • Air in fuel line

      		 Normally, value is 1530 mA or less An excessively large number is displayed due to a problem with fuel feed.
      "Target Pump SCV Current" in Data List is more than 1530 mA.
      Injection Feedback Val #1 (to #4)
      Judgment of Data List Values Problem Cause Normal Condition Diagnosis Note

      "Injection Feedback Val #1 (to #4)" in freeze frame data is not between -2.0 and 2.0 mm3/st

      		 Injector assembly malfunction or compression problem

      -2.0 to 2.0 mm3/st

      		 If an injector assembly is malfunctioning, even though the engine starts, idling is rough.

      "Injection Feedback Val #1 (to #4)" in Data List is not between -2.0 and 2.0 mm3/st when idling
      Injection Volume
      Judgment of Data List Values Problem Cause Normal Condition Diagnosis Note

      "Injection Volume" in Data List is 8 mm3/st or less and "Injection Feedback Val #1 (to #4)" is within range of +/-2 mm3/st when idling after warming up engine

      		 Injector assemblies of all cylinders malfunctioning - -
      Main Injection Period
      Judgment of Data List Values Problem Cause Normal Condition Diagnosis Note
      "Main Injection Period" in freeze frame data or Data List is 0 μs

      • Supply pump assembly (when suction control valve has open or short circuit, fuel supply from pump stops)

      • Problem with injection system (injector circuit is open (2 cylinders or more) or EDU (built into ECM) is malfunctioning)

      • Problem with engine immobiliser system

      • Engine speed 60 rpm or less

      • ECM malfunction

      		 - Indicates that fuel injection control has stopped.
      Immobiliser Communication
      Judgment of Data List Values Problem Cause Normal Condition Diagnosis Note
      "Immobiliser Communication" in freeze frame data or Data List is OFF Engine immobiliser system ON Fuel injection has stopped due to engine immobiliser system.

    NEXT

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