DTC P050A: Cold Start Idle Air Control System Performance: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Enter the following the menus: Powertrain / Engine and ECT / Trouble Codes.
5. Read the 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 → See step   21 

A: Go to next step 

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 engine switch on (IG) and turn the Techstream on.
3. Enter the following menus: Powertrain / Engine and ECT / Data List / Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2.
4. Read the values displayed on the Techstream.
5. 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.

   Result

   Total of Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2 values is between -20% and 20%.

NG → See step   5 

OK: Go to next step 

1. Check for deposits around the throttle valve and throttle valve condition.

   OK

   No deposits around throttle valve and throttle valve moves smoothly.

OK → See step   14 

NG → See step   4 

1. Repair or replace the throttle body. Refer to REMOVAL [01/2012 - ] .

NEXT → See step   14 

1. Allow the engine to idle.
2. Pinch the positive crankcase ventilation (PCV) hose.
3. Check the engine speed.

   OK

   The engine speed rises when the PCV hose is pinched.

NG → See step   10 

OK: Go to next step 

1. Check the air induction system for vacuum leakage. Refer to ON-VEHICLE INSPECTION [01/2012 - ] - Step 4 .

NG → See step   11 

OK: Go to next step 

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 → See step   12 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Start the engine.
3. Turn the Techstream on.
4. Warm up the engine.
5. Turn the A/C on.
6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Linear (Bank 1) or Control the VVT Linear (Bank 2).
7. Check the engine speed while operating the camshaft oil control valve using the Techstream.

   OK

   Techstream Operation	Engine 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, VVT OCV Duty #2 and VVT Change Angle #2]. Refer to DATA LIST / ACTIVE TEST [01/2012 - ] .

NG → See step   13 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF and Coolant Temp.
5. Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.
6. Read MAF with the engine speed at 3000 rpm.

   Standard

   Between 25.2 gm/s and 35.2 gm/s (shift lever: N; A/C: Off).

OK → See step   14 

NG → See step   15 

1. Repair or replace the PCV hose.

NEXT → See step   14 

1. Repair or replace the air induction system.

NEXT → See step   14 

1. Replace the air cleaner filter element sub-assembly.

NEXT → See step   14 

1. Check and repair the VVT system.

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs. Refer to DTC CHECK / CLEAR [01/2012 - ] .
5. Turn the engine switch off.
6. Turn the engine switch on (IG) and turn the Techstream on.
7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
8. Check that the engine coolant temperature is between - 10°C and 50°C (14 and 122°F).
9. Start the engine and warm it up.
10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
12. Input the DTC: P050A.
13. Check the DTC judgment result.

    Result

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

B → See step   15 

A → CHECK FOR INTERMITTENT PROBLEMS 

1. Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter and ECM. Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [01/2012 - ] .

   HINT: 

   Repair any problems.

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs. Refer to DTC CHECK / CLEAR [01/2012 - ] .
5. Turn the engine switch off.
6. Turn the engine switch on (IG) and turn the Techstream on.
7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
8. Check that the engine coolant temperature is between - 10°C and 50°C (14 and 122°F).
9. Start the engine and warm it up.
10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
12. Input the DTC: P050A.
13. Check the DTC judgment result.

    Result

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

B → END 

A: Go to next step 

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the mass air flow meter connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C3-3 (VG) - C53-74 (VG)	Always	Below 1 Ω
   C3-2 (E2G) - C53-75 (E2G)	Always	Below 1 Ω
   C3-3 (VG) or C53-74 (VG) (VG) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Replace the mass air flow meter assembly. Refer to REMOVAL [01/2012 - ] .

   HINT: 

   If the result of the inspection performed in step 9 indicated no problem, proceed to the next step without replacing the mass air flow meter assembly.

NEXT: Go to next step 

HINT: 

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.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs. Refer to DTC CHECK / CLEAR [01/2012 - ] .
5. Turn the engine switch off.
6. Turn the engine switch on (IG) and turn the Techstream on.
7. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
8. Check that the engine coolant temperature is between - 10°C and 50°C (14 and 122°F).
9. Start the engine and warm it up.
10. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
12. Input the DTC: P050A.
13. Check the DTC judgment result.

    Result

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

B → See step   20 

A → END