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 REFERENCE
  
  

  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 a Techstream. Freeze frame data record the engine condition when malfunctions are detected. 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 P050B) 
   1. Connect a Techstream to the DLC3.
   2. Turn the ignition switch ON.
   3. Turn the tester ON.
   4. Select the following menu items: 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.

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

   OK: 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 a Techstream to the DLC3.
   2. Turn the ignition switch ON.
   3. Turn the tester ON.
   4. Select the following menu items: 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. INSPECT THROTTLE WITH MOTOR BODY ASSEMBLY 
   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 ECM (see REMOVAL  ).

   NEXT: Go to step  15

5. PERFORM ACTIVE TEST USING TECHSTREAM (OCV OPERATION) 
   1. Connect a 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) 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	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 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. INSPECT 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 leak 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 (see REMOVAL  ).

   NEXT:Go to step  15

10. REPAIR OR REPLACE THROTTLE WITH MOTOR BODY ASSEMBLY 
    1. Repair or replace throttle with motor body assembly (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 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 a 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.

       OK: Stable fast idle 

    7. Read the DTCs.

       OK: No DTC is output. 

    NEXT: END