DTC P050A: Cold Start Idle Air Control System Performance: Procedure
- CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A)
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
- Read DTCs.RESULT
Result Proceed to DTC P050A is output A P050A and other DTCs are output B HINT:
If any DTCs other than P050A are output, troubleshoot those DTCs first.
NG → See step 20
OK: Go to next step
- READ VALUE USING TECHSTREAM (FUEL TRIM)
HINT:
Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter.
- Connect the Techstream to the DLC3.
- Start the engine and warm it up.
- Turn the Techstream on.
- Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Short FT #1 and Long FT #1.
- Read the values displayed on the Techstream.
- 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%.
NG → See step 5
OK: Go to next step
- INSPECT THROTTLE BODY
- Check for deposits around the throttle valve and check the throttle valve condition.
OK
No deposits around throttle valve and throttle valve moves smoothly.
OK → See step 14
NG → See step 4
- Check for deposits around the throttle valve and check the throttle valve condition.
- REPAIR OR REPLACE THROTTLE BODY
- Repair or replace the throttle body. Refer to REMOVAL .
NEXT → See step 14
- CHECK PCV HOSE
- Check the PCV hose connections. Refer to ON-VEHICLE INSPECTION - Step 1
.
OK
PCV hose is connected correctly and is not damaged.
NG → See step 10
OK: Go to next step
- Check the PCV hose connections. Refer to ON-VEHICLE INSPECTION - Step 1
.
- CHECK AIR INDUCTION SYSTEM
- Check the air induction system for vacuum leaks. Refer to ON-VEHICLE INSPECTION
.
OK
No leaks in air induction system.
NG → See step 11
OK: Go to next step
- Check the air induction system for vacuum leaks. Refer to ON-VEHICLE INSPECTION
.
- INSPECT AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
- 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 → See step 12
OK: Go to next step
- Visually check that the air cleaner filter element is not excessively contaminated with dirt or oil.
- PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE OCV)
- Connect the Techstream to the DLC3.
- Start the engine.
- Turn the Techstream on.
- Warm up the engine.
- Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT System (Bank 1).
- Check the engine speed while operating the Oil Control Valve (OCV) using the Techstream.
OK
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 → See step 13
OK: Go to next step
- READ VALUE USING TECHSTREAM (MAF)
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF and Coolant Temp.
- Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.
- Read MAF with the engine speed at 3000 rpm.
Standard
Between 9.38 g/sec. and 14.08 g/sec. (shift lever: N; A/C: Off).
OK → See step 14
NG → See step 15
- REPAIR OR REPLACE PCV SYSTEM
- Repair or replace the PCV hose.
NEXT → See step 14
- REPAIR OR REPLACE AIR INDUCTION SYSTEM
- Repair or replace the air induction system.
NEXT → See step 14
- REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
- Replace the air cleaner filter element sub-assembly.
NEXT → See step 14
- CHECK AND REPAIR VVT SYSTEM
- Check and repair the VVT system.
NEXT: Go to next step
- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A) NOTE:
In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Clear DTCs. Refer to DTC CHECK / CLEAR .
- Turn the ignition switch off.
- Turn the ignition switch to ON and turn the Techstream on.
- Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
- Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
- Start the engine and warm it up.
- Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
- Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
- Input the DTC: P050A.
- 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 → See step 22
- CHECK HARNESS AND CONNECTOR
- 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
.
HINT:
Repair any problems.
NEXT: Go to next step
- 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
.
- CHECK WHETHER DTC OUTPUT RECURS NOTE:
In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Clear DTCs. Refer to DTC CHECK / CLEAR .
- Turn the ignition switch off.
- Turn the ignition switch to ON and turn the Techstream on.
- Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
- Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
- Start the engine and warm it up.
- Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
- Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
- Input the DTC: P050A.
- 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
- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- Disconnect the mass air flow meter connector.
- Disconnect the ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition B1-5 (VG) - B30-94 (VG) Always Below 1 Ω B1-4 (E2G) - B30-117 (E2G) Always Below 1 Ω B1-5 (VG) or B30-94 (VG) - Body ground Always 10 kΩ or higher
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- REPLACE MASS AIR FLOW METER
- Replace the mass air flow meter. Refer to REMOVAL
.
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
- Replace the mass air flow meter. Refer to REMOVAL
.
- CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED NOTE:
In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Clear DTCs. Refer to DTC CHECK / CLEAR .
- Turn the ignition switch off.
- Turn the ignition switch to ON and turn the Techstream on.
- Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
- Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
- Start the engine and warm it up.
- Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
- Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
- Input the DTC: P050A.
- Check the DTC judgment result.RESULT
Result Proceed to NORMAL (DTC is not output) A ABNORMAL (DTC P050A is output) B
B → See step 21
A → END
- GO TO DIAGNOSTIC TROUBLE CODE CHART
- REPLACE ECM. Refer to REMOVAL
- GO TO CHECK FOR INTERMITTENT PROBLEMS