SFI SYSTEM, Diagnostic DTC:P050B

DTC Code DTC Name
P050B Cold Start Ignition Timing Performance

MONITOR DESCRIPTION

This monitor will run when the engine is started at an engine coolant temperature of -10 to 50°C (14 to 122°F). The DTC is stored after the engine idles for 13 seconds or more (2 trip detection logic).

The DTC is designed to monitor the ignition timing at cold start. When the engine is started at an engine coolant temperature of below 50°C (122°F), the ECM checks the ignition timing during engine idling. If the ignition timing advances beyond the specified level within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is set when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

The electronic throttle control system controls the idle speed. The electrical throttle control system operates the throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the target idle speed.

Note

When the negative (-) battery terminal is disconnected during inspection or repairs, the idle speed control learned values are cleared. Idle speed control learning is performed when the engine has been warmed up and idled for 5 minutes because this DTC cannot be set after the idle speed control learned values are cleared.

Tech Tips

Idle speed control learning is performed when the engine is warmed up and has been idling 5 minutes.

A01FHYHE01
DTC No. DTC Detection Condition Trouble Area
P050B Insufficient ignition timing retard and cold start (2 trip detection logic)

  • Throttle body with motor assembly

  • Mass air flow meter

  • Intake system

  • PCV system

  • VVT system

  • Air cleaner filter element sub-assembly

  • Wire harness or connector

  • ECM

MONITOR STRATEGY

Required Sensors/Components (Main) Throttle body with motor assembly
Required Sensors/Components (Related) Engine coolant temperature sensor, mass air flow meter
Frequency of Operation Once per driving cycle

TYPICAL MALFUNCTION THRESHOLDS

Accumulated time when ignition timing retard is cut off 8 seconds or more

CONFIRMATION DRIVING PATTERN


  1. Connect the GTS to the DLC3.

  2. Turn the engine switch on (IG) and turn the GTS on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Click here.

  4. Turn the engine switch off and wait for at least 30 seconds.

  5. Turn the engine switch on (IG) and turn the GTS on [A].

  6. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

  7. Check that "Coolant Temp" in the Data List is within the range of -10 to 50°C (14 to 122°F).

  8. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the freeze frame data.

  9. Idle the engine for 1 minute or more [B].

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

  11. Read the pending DTC [C].

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  13. Input the DTC: P050B.

  14. Check the DTC judgment result.

    GTS Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU's memory limit

    Tech Tips


    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows INCOMPLETE or N/A, idle the engine for 3 minutes, let the engine cool down, and then perform steps [A] through [C] again.

INSPECTION PROCEDURE

Tech Tips


  • DTC P050B may be set when the engine shows the symptom as listed below. If necessary, check the trouble area as listed below.

    Symptom Factor Trouble Area

    Low idle speed at engine cold

    (immediately after engine start)

    		 Excessive engine friction

    • Engine oil deterioration

    • Drive belt tension

    • Cooler compressor assembly

    • Generator assembly

    Rough idle at engine cold

    (immediately after engine start)

    		 Abnormal combustion Fuel quality

  • Read freeze frame data using the GTS. 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.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050B)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P050B is output A
      DTC P050B and other DTCs are output B

      Tech Tips

      If any DTCs other than P050B are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. READ VALUE USING GTS (FUEL TRIM)

    Tech Tips

    Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter.


    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Short FT #1, Long FT #1, Short FT #2 and Long FT #2.

    5. Read the values displayed on the GTS.

    6. Add together the Short FT #1 and Long FT #1 values, and the Short FT #2 and Long FT #2 values to obtain the total fuel trim.

      OK
      The total of the Short FT #1 and Long FT #1 values, and the total of the Short FT #2 and Long FT #2 values is between -20% and 20%.

    NG

    CHECK PCV SYSTEM Click here

    OK

  3. INSPECT THROTTLE BODY WITH MOTOR ASSEMBLY (THROTTLE VALVE)


    1. Inspect that there are no deposits around the throttle valve and throttle valve condition.

      OK
      No deposits around throttle valve and throttle valve moves smoothly.
      Result
      Result Proceed to
      NG A
      OK B

    B

    CHECK WHETHER DTC OUTPUT RECURS (DTC P050B) Click here

    A

  4. REPAIR OR REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY


    1. Repair or replace throttle body with motor assembly Click here.


    NEXT

    CHECK WHETHER DTC OUTPUT RECURS (DTC P050B) Click here

  5. CHECK PCV SYSTEM


    1. Check the PCV hose connections Click here.

      OK
      PCV valve and hose are connected correctly and are not damaged.

    NG

    REPAIR OR REPLACE PCV HOSE Click here

    OK

  6. CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leakage Click here.

      OK
      No leakage from intake system.

    NG

    REPAIR OR REPLACE INTAKE SYSTEM Click here

    OK

  7. CHECK AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY


    1. Visually check that the air cleaner filter element is not excessively contaminated with dirt or oil.

      OK
      Air cleaner filter element is not excessively contaminated with dirt or oil.

    NG

    REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY Click here

    OK

  8. PERFORM ACTIVE TEST USING GTS (CONTROL THE VVT LINEAR)


    1. Operate the VVT system through the Active test, and check if the VVT system is operating normally.


      1. Perform the Active Test, referring to DTC P0011 Inspection Procedure (VVT system for intake camshaft) Click here.

      2. Perform the Active Test, referring to DTC P0014 Inspection Procedure (VVT system for exhaust camshaft) Click here.


    NG

    CHECK AND REPAIR VVT SYSTEM Click here

    OK

  9. READ VALUE USING GTS (MAF)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / MAF and Coolant Temp.

    5. Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

    6. Read MAF with the engine speed at 3000 rpm.

      Standard
      Between 7.60 gm/sec and 11.40 gm/sec (shift lever: N, A/C: Off).

    OK

    CHECK WHETHER DTC OUTPUT RECURS (DTC P050B) Click here

    NG

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION) Click here

  10. REPAIR OR REPLACE PCV HOSE


    1. Repair or replace the PCV valve or hose.


    NEXT

    CHECK WHETHER DTC OUTPUT RECURS (DTC P050B) Click here

  11. REPAIR OR REPLACE INTAKE SYSTEM


    1. Repair or replace the intake system.


    NEXT

    CHECK WHETHER DTC OUTPUT RECURS (DTC P050B) Click here

  12. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY


    1. Replace the air cleaner filter element sub-assembly.


    NEXT

    CHECK WHETHER DTC OUTPUT RECURS (DTC P050B) Click here

  13. CHECK AND REPAIR VVT SYSTEM


    1. Check and repair the VVT system.

      Tech Tips


      • Refer to DTC P0011 Inspection Procedure (VVT system for intake camshaft) Click here.

      • Refer to DTC P0014 Inspection Procedure (VVT system for exhaust camshaft) Click here.


    NEXT

  14. CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

    Note

    In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Turn the engine switch off and wait for at least 30 seconds.

    6. Turn the engine switch on (IG) and turn the GTS on.

    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

    8. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F)

    9. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the freeze frame data.

    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    12. Input the DTC: P050B.

    13. Check the DTC judgment result.

      Result
      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P050B is output) B

    B

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION) Click here

    A

    END

  15. CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

    Note

    In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Turn the engine switch off and wait for at least 30 seconds.

    6. Turn the engine switch on (IG) and turn the GTS on.

    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

    8. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F)

    9. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the freeze frame data.

    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    12. Input the DTC: P050B.

    13. Check the DTC judgment result.

      Result
      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P050B is output) B

    B

    CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION) Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  16. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)


    1. Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter and ECM Click here.

      Tech Tips

      Repair any problems.


    NEXT

  17. CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

    Note

    In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Turn the engine switch off and wait for at least 30 seconds.

    6. Turn the engine switch on (IG) and turn the GTS on.

    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

    8. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F)

    9. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the freeze frame data.

    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    12. Input the DTC: P050B.

    13. Check the DTC judgment result.

      Result
      Result Proceed to
      ABNORMAL (DTC P050B is output) A
      NORMAL (DTC is not output) B

    B

    END

    A

  18. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)


    1. Disconnect the mass air flow meter connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      F39-5 (VG) - F1-25 (VG) Always Below 1 Ω
      F39-4 (E2G) - F1-24 (E2G) Always Below 1 Ω
      F39-5 (VG) or F1-25 (VG) - Body ground Always 10 kΩ or higher

    4. Reconnect the mass air flow meter connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  19. REPLACE MASS AIR FLOW METER


    1. Replace the mass air flow meter Click here.

      Tech Tips

      If the result of the inspection performed in step 9 indicated no problem, proceed to the next step without replacing the mass air flow meter assembly.


    NEXT

  20. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    Note

    In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs Click here.

    5. Turn the engine switch off and wait for at least 30 seconds.

    6. Turn the engine switch on (IG) and turn the GTS on.

    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

    8. Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

    9. Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the freeze frame data.

    10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    12. Input the DTC: P050B.

    13. Check the DTC judgment result.

      Result
      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P050B is output) B

    B

    REPLACE ECM Click here

    A

    END