P050A
1UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P050A: Cold Start Idle Air Control System Performance
P050A - Cold Start Idle Air Control System Performance
DESCRIPTION
This monitor will run when the engine is started with the engine coolant temperature at -10 to 60°C (14 to 140°F). The DTC will be stored after the engine idles for 13 seconds (2 trip detection logic).
The DTC is designed to monitor the idle air control at cold start. When the engine is started with the engine coolant temperature below 60°C (140°F), the ECM measures the accumulated mass air flow while the engine is idling. If it does not reach the threshold within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is stored when the malfunction is detected in consecutive driving cycles (2 trip detection logic).
The ETCS (Electronic Throttle Control System) controls the idle speed. The ETCS operates the throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the target idle speed.
NOTICE:
When the cable is disconnected from the negative battery terminal during inspections or repairs, the ISC (Idle Speed Control) learned values are cleared. This DTC cannot be stored with the ISC learned values cleared.
HINT
ISC learning is performed when the engine is warmed up and has been idling for 5 minutes.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG) and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.
4. Turn the engine switch off and wait for 30 seconds.
5. Turn the engine switch on (IG) and turn the Techstream on [A].
6. Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
7. Check that "Coolant Temp" in the Data List is within the range of -10 to 60°C (14 to 140°F).
8. Start the engine and warm it up until the coolant temperature is the same as the coolant temperature in the freeze frame data.
9. Idle the engine for 1 minute or more [B].
10. Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.
11. Read the pending DTC [C].
HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
12. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
13. Input the DTC: P050A.
14. Check the DTC judgment result.
HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows INCOMPLETE or UNKNOWN, idle the engine for 3 minutes, let the engine cool down, and then perform steps [A] and [B] again.
15. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
16. Check the DTC judgment result.
HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
17. If the test result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
INSPECTION PROCEDURE
HINT
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.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Result:
HINT
If any DTCs other than P050A are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART SFI System
A -- Continue 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.
(a) Connect the Techstream to the DLC3.
(b) Start the engine.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Data List / All Data / Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2.
(e) Read the values displayed on the Techstream at engine idle.
(f) 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 -- CHECK PCV HOSE (CONNECTIONS)
OK -- Continue to next step.
3. INSPECT THROTTLE BODY ASSEMBLY
(a) Check for deposits around the throttle valve and check the throttle valve condition.
OK:
No deposits around throttle valve and throttle valve moves smoothly.
Result:
B -- CHECK WHETHER DTC OUTPUT RECURS
A -- Continue to next step.
4. REPAIR OR REPLACE THROTTLE BODY ASSEMBLY
(a) Repair or replace the throttle body assembly Removal.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS
5. CHECK PCV HOSE (CONNECTIONS)
(a) Check the PCV hose connections.
OK:
PCV hose is connected correctly and is not damaged.
NG -- REPAIR OR REPLACE PCV HOSE
OK -- Continue to next step.
6. CHECK AIR INDUCTION SYSTEM
(a) Check the air induction system for vacuum leaks.
OK:
No leaks in air induction system.
NG -- REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK -- Continue to next step.
7. INSPECT AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
(a) 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 -- REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
OK -- Continue to next step.
8. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT-IE LINEAR)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG) and turn the Techstream on.
(c) Start the engine and warm it up.
(d) Enter the following menus: Powertrain / Engine / Active Test / Control the VVT-iE Linear (Bank 1) or Control the VVT-iE Linear (Bank 2) / VVT-iE Aim Angle #1 and VVT-iE Change Angle #1 or VVT-iE Aim Angle #2 and VVT-iE Change Angle #2.
(e) Perform the Active Test operation with the engine speed at 1500 rpm.
OK:
NG -- CHECK AND REPAIR VVT SYSTEM
OK -- Continue to next step.
9. READ VALUE USING TECHSTREAM (MAF)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Data List / All Data / MAF and Coolant Temp.
(e) Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.
(f) Read MAF with the engine speed at 3000 rpm.
Standard:
Between 18 g/sec. and 22 g/sec. (shift lever: N; A/C: Off).
NG -- CHECK HARNESS AND CONNECTOR
OK -- CHECK WHETHER DTC OUTPUT RECURS
10. REPAIR OR REPLACE PCV HOSE
(a) Repair or replace the PCV hose.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS
11. REPAIR OR REPLACE AIR INDUCTION SYSTEM
(a) Repair or replace the air induction system.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS
12. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
(a) Replace the air cleaner filter element sub-assembly.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS
13. CHECK AND REPAIR VVT SYSTEM
(a) Check and repair the VVT system.
NEXT -- Continue to next step.
14. CHECK WHETHER DTC OUTPUT RECURS
NOTICE:
In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the engine switch off.
(f) Turn the engine switch on (IG) and turn the Techstream on.
(g) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.
(h) Check that the engine coolant temperature is between -10°C and 60°C (14 and 140°F).
(i) Start the engine and warm it up.
(j) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(k) Enter the following menus: Powertrain / Engine / Utility / All Readiness.
(l) Input the DTC: P050A.
(m) Check the DTC judgment result.
Result
B -- CHECK HARNESS AND CONNECTOR
A -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems
15. CHECK HARNESS AND CONNECTOR
(a) Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter and ECM Electronic Circuit Inspection Procedure.
HINT
Repair any problems.
NEXT -- Continue to next step.
16. CHECK WHETHER DTC OUTPUT RECURS
NOTICE:
In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the engine switch off.
(f) Turn the engine switch on (IG) and turn the Techstream on.
(g) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.
(h) Check that the engine coolant temperature is between -10°C and 60°C (14 and 140°F).
(i) Start the engine and warm it up.
(j) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(k) Enter the following menus: Powertrain / Engine / Utility / All Readiness.
(l) Input the DTC: P050A.
(m) Check the DTC judgment result.
Result
B -- END
A -- Continue to next step.
17. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
(a) Disconnect the MAF meter connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance between the terminals.
Standard resistance (Check for Open):
Standard resistance (Check for Short):
(d) Reconnect the MAF meter connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
18. REPLACE MASS AIR FLOW METER ASSEMBLY
(a) Replace the mass air flow meter assembly 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 -- Continue to next step.
19. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
NOTICE:
In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the engine switch off.
(f) Turn the engine switch on (IG) and turn the Techstream on.
(g) Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.
(h) Check that the engine coolant temperature is between -10°C and 60°C (14 and 140°F).
(i) Start the engine and warm it up.
(j) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(k) Enter the following menus: Powertrain / Engine / Utility / All Readiness.
(l) Input the DTC: P050A.
(m) Check the DTC judgment result.
Result
B -- REPLACE ECM Removal
A -- END