DTC    P050A    Cold Start Idle Air Control System Performance

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DESCRIPTION

This monitor will run when the engine is started with the engine coolant temperature at -10 to 50°C (14 to 122°F). The DTC will be stored after the engine idles for 13 seconds (2 trip detection logic).
The DTC is designed to monitor the idle air control at cold start. When the engine is started with the engine coolant temperature at lower than 50°C (122°F), the ECM measures the accumulated mass air flow at engine idling. If it does not reach the criteria within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is stored when the malfunction is detected in consecutive driving cycles (2 trip detection logic).
The electronic throttle control system controls the idle speed. The electronic 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.

NOTICE:
When the cable is disconnected from the negative battery terminal during inspections or repairs, the idle speed control learning values are cleared. This DTC cannot be stored with the idle speed control learning values cleared.

HINT:
The idle speed control learning is performed when the engine is warmed up and has been idling for 5 minutes.

A124205E14


DTC No.
DTC Detection Condition
Trouble Area
P050A
Insufficient mass air flow at cold start
(2 trip detection logic)
  1. Throttle body assembly
  2. Mass air flow meter
  3. PCV hose
  4. Air cleaner filter element sub-assembly
  5. Intake system
  6. VVT system
  7. Wire harness or connector
  8. ECM

MONITOR STRATEGY


Related DTCs
P050A: Cold Start Idle Air Speed Control System
Required sensors/Components (Main)
Throttle body assembly
Required sensors/Components (Related)
Mass air flow meter
Engine coolant temperature sensor
Frequency of operation
Once per driving cycle
Duration
10 seconds
MIL operation
2 driving cycles
Sequence of operation
None

TYPICAL ENABLING CONDITIONS


Monitor runs whenever following DTCs not present
P0010 (VVT Oil Control Valve)
P0011 (VVT System - Advance)
P0012 (VVT System - Retard)
P0016 (VVT System - Misalignment)
P0102, P0103 (Mass Air Flow Meter)
P0115, P0117, P0118 (Engine Coolant Temperature Sensor)
P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135 (Throttle Position Sensor)
P0125 (Insufficient Engine Coolant Temperature Sensor for Closed Loop Fuel Control)
P014C, P014D, P015A, P015B, P2195, P2196, P2237, P2238, P2239, P2252, P2253 (Air Fuel Ratio Sensor)
P0171, P0172 (Fuel System)
P0301 - P0304 (Misfire)
P0335 (Crankshaft Position Sensor)
P0340 (Camshaft Position Sensor)
P0351 - P0354 (Igniter)
P0500 (Vehicle Speed Sensor)
P0705 (Shift Lever Position Switch)
Battery voltage
8 V or more
Time after engine start
3 seconds or more
Starter
OFF
Engine coolant temperature at engine start
-10°C (14°F) or more
Engine coolant temperature
-10 to 50°C (14 to 122°F)
Engine idling time
3 seconds or more
Fuel-cut
OFF
Vehicle speed
Less than 3 km/h (1.875 mph)
Time after shift position changed
1 second or more
Atmospheric pressure
76 kPa(abs) [570 mmHg(abs)] or more

TYPICAL MALFUNCTION THRESHOLDS


Accumulated mass air flow
A/T: Less than 22.5 g (varies with engine coolant temperature)
M/T: Less than 17.5 g (varies with engine coolant temperature)

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
  4. Turn the ignition switch off and wait for at least 30 seconds.
  5. Turn the ignition switch to ON and turn the Techstream 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 coolant temperature is the same as the 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 [C].
  11. Read pending DTCs.

    HINT:
    1. If a pending DTC is output, the system is malfunctioning.
    2. 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: P050A.
  14. Check the DTC judgment result.

    Techstream Display
    Description
    NORMAL
    1. DTC judgment completed
    2. System normal
    ABNORMAL
    1. DTC judgment completed
    2. System abnormal
    INCOMPLETE
    1. DTC judgment not completed
    2. Perform driving pattern after confirming DTC enabling conditions
    N/A
    1. Unable to perform DTC judgment
    2. Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:
    1. If the judgment result shows NORMAL, the system is normal.
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
    3. 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.
  15. If no pending DTC is output, perform a universal trip and check for permanent DTCs (Click here).

    HINT:
    1. If a permanent DTC is output, the system is malfunctioning.
    2. If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0102 (Click here).

INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:
Read freeze frame data using the Techstream. 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.
1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A)
  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch ON.

  1. Turn the Techstream on.

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

  1. Read DTCs.

    Result 
    Result
    Proceed to
    DTC P050A is output
    A
    DTC P050A and other DTCs are output
    B

    HINT:
    If any DTCs other than P050A are output, troubleshoot those DTCs first.


B
GO TO DTC CHART (Click here)
A


2.READ VALUE USING TECHSTREAM (FUEL TRIM)

HINT:
Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter.
  1. Connect the Techstream to the DLC3.

  1. Start the engine.

  1. Turn the Techstream on.

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

  1. Read the values displayed on the Techstream at engine idle.

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

    Standard:
    Total of Short FT #1 and Long FT #1 values is between -20% and 20%.


NG
Go to step 5
OK


3.INSPECT THROTTLE BODY ASSEMBLY (THROTTLE VALVE)
  1. Check that there are no deposits around the throttle valve and throttle valve condition.

    OK:
    No deposits around throttle valve and throttle valve moves smoothly.


OK
Go to step 14

NG
Go to step 4

4.REPAIR OR REPLACE THROTTLE BODY ASSEMBLY
  1. Repair or replace throttle body assembly (Click here).



NEXT
Go to step 14

5.CHECK PCV HOSE CONNECTIONS
  1. Check the PCV hose connections (Click here).

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


NG
Go to step 10
OK


6.CHECK INTAKE SYSTEM
  1. Check the intake system for vacuum leaks (Click here).

    OK:
    No leaks from the intake system.


NG
Go to step 11
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:
    The air cleaner filter element is not excessively contaminated with dirt or oil.


NG
Go to step 12
OK


8.PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY)
  1. Connect the Techstream to the DLC3.

  1. Start the engine.

  1. Turn the Techstream on.

  1. Turn the A/C switch on.

  1. Warm up the engine.

  1. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Linear (Bank 1).

  1. Check the engine speed while operating the camshaft timing oil control valve assembly using the Techstream.

    OK:

    Techstream Operation
    Specified Condition
    0%
    Normal engine speed
    100%
    Engine idles roughly or stalls

    HINT:
    Refer to "Data List / Active Test" [VVT OCV Duty #1, VVT Change Angle #1] (Click here).


NG
Go to step 13
OK


9.READ VALUE USING TECHSTREAM (MAF)
  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

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

  1. Read MAF with the engine speed at 2500 rpm.

    Standard:

    Techstream Display
    Condition
    Specified Condition
    MAF
    Shift lever position: N
    A/C: Off
    Engine Speed: 2500 rpm
    Between 8.0 gm/sec. and 14.7 gm/sec.


OK
Go to step 14

NG
Go to step 15

10.REPAIR OR REPLACE PCV HOSE
  1. Repair or replace the PCV hose.



NEXT
Go to step 14

11.REPAIR OR REPLACE INTAKE SYSTEM
  1. Repair or replace the intake system.



NEXT
Go to step 14

12.REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
  1. Replace the air cleaner filter element sub-assembly.



NEXT
Go to step 14

13.CHECK AND REPAIR VVT SYSTEM
  1. Check and repair the VVT system.

    HINT:
    Refer to DTC P0011 Inspection Procedure (Click here).

NEXT


14.CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)

NOTICE:
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 Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Clear DTCs (Click here).

  1. Turn the ignition switch off and wait for at least 30 seconds.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

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

  1. Start the engine and warm it up.

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

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

  1. Input the DTC: P050A.

  1. Check the DTC judgment result.

    Result 
    Result
    Proceed to
    NORMAL (DTC is not output)
    A
    ABNORMAL (DTC P050A is output)
    B


B
Go to step 15
A

CHECK FOR INTERMITTENT PROBLEMS (Click here)  

15.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).

    HINT:
    Repair any problems.

NEXT


16.CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)

NOTICE:
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 Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Clear DTCs (Click here).

  1. Turn the ignition switch off and wait for at least 30 seconds.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

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

  1. Start the engine and warm it up.

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

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

  1. Input the DTC: P050A.

  1. Check the DTC judgment result.

    Result 
    Result
    Proceed to
    ABNORMAL (DTC P050A is output)
    A
    NORMAL (DTC is not output)
    B


B
END
A


17.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
  1. Disconnect the mass air flow meter connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    Condition
    Specified Condition
    M1-3 (VG) - E5-28 (VG)
    Always
    Below 1 Ω
    M1-2 (E2G) - E5-30 (E2G)

    Standard Resistance (Check for Short):
    Tester Connection
    Condition
    Specified Condition
    M1-3 (VG) or E5-28 (VG)) - Body ground
    Always
    10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


18.REPLACE MASS AIR FLOW METER
  1. Replace the mass air flow meter (Click here).

    HINT:
    If the results of the inspections performed in step 9 indicated no problem, proceed to the next step without replacing the mass air flow meter.

NEXT


19.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

NOTICE:
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 Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Clear DTCs (Click here).

  1. Turn the ignition switch off and wait for at least 30 seconds.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

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

  1. Start the engine and warm it up.

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

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

  1. Input the DTC: P050A.

  1. Check the DTC judgment result.

    Result 
    Result
    Proceed to
    NORMAL (DTC is not output)
    A
    ABNORMAL (DTC P050A is output)
    B


B
REPLACE ECM (Click here)
A

END