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.
  DIAGNOSTIC TROUBLE CODE 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 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.

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050B) 
   1. Connect the intelligent tester to the DLC3.
   2. Turn the ignition switch to the ON position.
   3. Turn the tester on.
   4. Select the following the menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
   5. Read the DTCs.

      Result 

      RESULT CHART
      
      

      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.

   NG:  GO TO DTC CHART 

   OK: Go to Next Step 

2. READ VALUE USING INTELLIGENT TESTER (FUEL TRIM) 

   HINT:

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

   1. Connect the intelligent tester to the DLC3.
   2. Start the engine and warm it up.
   3. Turn the tester on.
   4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / SHORT FT #1 (or #2) and LONG FT #1 (or #2).
   5. Read the values displayed on the tester.
   6. Add together the SHORT FT #1 (or #2) and LONG FT #1 (or #2) values to obtain the total FUEL TRIM.

      OK: Total of SHORT FT #1 (or #2) and LONG FT #1 (or #2) values is between -20 % and 20 %. 

   NG:  Go to step  5

   OK: Go to Next Step 

3. CHECK THROTTLE BODY 
   1. Check that there are no deposits around the throttle valve.

      OK: No deposits around the throttle valve 

   NG:  Go to step  10

   OK: Go to Next Step 

4. REPLACE ECM 

   NEXT:  Go to step  15

5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (OCV OPERATION) 
   1. Connect the intelligent tester to the DLC3.
   2. Start the engine and warm it up.
   3. Turn the tester on.
   4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / VVT CTRL B1 (or VVT CTRL B2).
   5. Using the intelligent tester, operate the Oil Control Valve (OCV) and check the engine speed.

      OK 

      TESTER CONNECTION SPECIFIED CONDITION 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  11

   OK: Go to Next Step 

6. CHECK PCV SYSTEM 
   1. Start the engine.
   2. Pinch the positive crankcase ventilation (PCV) hose.
   3. Check the engine RPM.

      OK: The engine RPM rises when the PCV hose is pinched. 

   NG:  Go to step  12

   OK: Go to Next Step 

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  13

   OK: Go to Next Step 

8. CHECK AIR INDUCTION SYSTEM 
   1. Check the air induction system for vacuum leaks.

      OK: No leakage from the air induction system. 

   NG:  Go to step  14

   OK: Go to Next Step 

9. REPLACE MASS AIR FLOW METER 

   NEXT:  Go to step  15

10. REPAIR OR REPLACE THROTTLE BODY 

    NEXT:  Go to step  15

11. CHECK AND REPAIR VVT SYSTEM 

    NEXT:  Go to step  15

12. REPAIR OR REPLACE PCV SYSTEM 

    NEXT:  Go to step  15

13. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY 

    NEXT:  Go to step  15

14. REPAIR OR REPLACE AIR INDUCTION SYSTEM 

    NEXT: Go to step 15 

15. CHECK WHETHER DTC OUTPUT RECURS (DTC P050B) 
    NOTE: For this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
    1. Connect the intelligent tester to the DLC3.
    2. Turn the ignition switch to the ON position.
    3. Turn the tester on.
    4. Clear the DTCs (See DTC CHECK / CLEAR  ).
    5. Switch the ECM from normal mode to check mode using the tester (See CHECK MODE PROCEDURE  ).
    6. Start the engine and idle it for one minute.

       OK: Stable fast idle 

    7. Read the DTCs.

       OK: No DTC is output. 

    NEXT: END