Inspection Procedure

HINT:

• DTC P050B may be set when the engine has the symptoms listed below. If necessary, check the trouble areas listed below.
  SYMPTOMS CHART
  
  

  Symptoms	Factor	Trouble Area
  Low idle speed when engine is cold (immediately after engine start)	Excessive engine friction	Engine oil deterioration Drive belt tension A/C compressor Generator P/S pump
  Rough idle when engine is cold (immediately after engine start)	Abnormal combustion	Fuel quality

• 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 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 Techstream to the DLC3.
   2. Turn the ignition switch ON
   3. Turn the tester ON
   4. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.
   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 

   A: Go to Next Step 

2. READ VALUE OF 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.
   2. Turn the ignition switch ON.
   3. Turn the tester ON.
   4. Enter the following menus: Powertrain/Engine and ECT/Data List/A/F Control System/Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2.
   5. Read the values displayed on the tester.
   6. Add together the Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2 values to obtain the total fuel trim.

      OK: Total of Short FT #1 and Long FT #1, or Short FT #2 and Long FT #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 
   1. Replace the ECM (see REMOVAL  ).

   NEXT: Go to step  15

5. PERFORM ACTIVE TEST BY TECHSTREAM (OCV OPERATION) 
   1. Connect the Techstream to the DLC3.
   2. Start the engine and turn the tester ON.
   3. Warm up the engine.
   4. Enter the following menus: Powertrain/Engine and ECT/Active Test/Control the VVT System (Bank 1) or Control the VVT System (Bank 2).
   5. Check the engine speed while operating the Oil Control Valve (OCV) using the tester.

      OK 

      TESTER OPERATION AND SPECIFIED CONDITION
      
      

      Tester Operation	Specified Condition
      OCV OFF	Normal engine speed
      OCV ON	Soon after OCV switched from OFF to ON, engine idles roughly or stalls

   NG: Go to step  11

   OK: Go to Next Step 

6. CHECK PCV SYSTEM 
   1. Start the engine.
   2. Pinch the 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 
   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 
   1. Replace the mass air flow meter.

   NEXT: Go to step  15

10. REPAIR OR REPLACE THROTTLE BODY 
    1. Repair or replace the throttle body (see REMOVAL  ).

    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 

    NEXT: Go to step  15

14. REPAIR OR REPLACE AIR INDUCTION SYSTEM 
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 Techstream to the DLC3.
    2. Turn the ignition switch ON.
    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.
    7. Check that the idling is stable and fast.

       OK: Stable fast idle 

    8. Read the DTCs.

       OK: No DTC is output. 

    NEXT: END