Inspection Procedure

HINT:

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

  Symptoms	Factor	Trouble Area
  Low idle speed at engine cold.	Excessive engine friction	Engine oil deterioration Drive belt tension A/C compressor Generator P/S pump
  Rough idle at engine cold.	Abnormal combustion	Fuel quality

• Read freeze frame data using 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 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.

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050B) 
   1. Connect Techstream to the DLC3.
   2. Turn the engine switch on (IG).
   3. Turn the tester on.
   4. Select the following the menu items: Powertrain / Engine and ECT / Trouble Code.
   5. Read the DTCs.

   Result 

   RESULT REFERENCE
   
   

   Display (DTC Output)	Proceed to
   P050B	A
   P050B and other DTCs	B

   HINT:

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

   B: GO TO DTC CHART  (See DIAGNOSTIC TROUBLE CODE CHART )

   A: Go to next step 

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 Techstream to the DLC3.
   2. Start the engine.
   3. Turn the tester on.
   4. Select the following menu items: Powertrain / Engine and ECT / Data List / Short FT #1 and Long FT #1.
   5. Read the values displayed on the tester at engine idles.
   6. Add together the Short FT #1 and Long FT #1 values to obtain the total FUEL TRIM.

      OK: 

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

      OK: Go to step   12 

      NG: Go to next step 

3. PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE OCV) 
   1. Connect Techstream to the DLC3.
   2. Start the engine and turn the tester on.
   3. Warm up the engine.
   4. Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the VVT System (Bank 1).
   5. Check the engine speed while operating the Oil Control Valve (OCV) using the tester.

      OK 

   TESTER OPERATIONS SPECIFIED CONDITIONS CHART
   
   

   Tester Operation	Specified Condition
   OCV OFF	Normal engine speed
   OCV ON	Engine idles roughly or stalls (soon after OCV switched from OFF to ON)

   NG: Go to step   8 

   OK: Go to next step 

4. CHECK PCV HOSE CONNECTIONS 

   OK: 

   PCV hose is connected correctly and is not damaged. 

   NG: Go to step   9 

   OK: Go to next step 

5. CHECK INTAKE SYSTEM 
   1. Check the intake system for vacuum leakage (See ON-VEHICLE INSPECTION ).

   OK: 

   No leakage from intake system. 

   NG: Go to step   10 

   OK: Go to next step 

6. 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: Go to step   11 

   OK: Go to next step 

7. REPLACE MASS AIR FLOW METER 
   1. Replace mass air flow meter (See ON-VEHICLE INSPECTION ).

   NEXT: Go to step   15 

8. CHECK AND REPAIR VVT SENSOR 

   NEXT: Go to step   15 

9. REPAIR OR REPLACE PCV HOSE 

   NEXT: Go to step   15 

10. REPAIR OR REPLACE INTAKE SYSTEM 

    NEXT: Go to step   15 

11. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY 

    NEXT: Go to step   15 

12. CHECK THROTTLE VALVE 
    1. Check for deposits around the throttle valve and throttle valve condition.

    OK: 

    No deposits around throttle valve and throttle valve moves smoothly. 

    NG: Go to step   14 

    OK: Go to next step 

13. REPLACE ECM 
    1. Replace ECM (See REMOVAL ).

    NEXT: Go to step   15 

14. REPAIR OR REPLACE THROTTLE BODY ASSEMBLY 

    NEXT: Go to step   15 

15. CHECK WHETHER DTC OUTPUT RECURS (DTC P050B) 
    NOTE: In this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
    1. Connect Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the tester on.
    4. Clear the DTCs.
    5. Switch the ECM from normal mode to check mode using the tester.
    6. Start the engine to idle for a minute.

       OK: 

       Stable fast idling. 

    7. Read the DTCs.

       OK: 

       No DTC output. 

       NEXT: END