P050A
2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P050A: Cold Start Idle Air Control System Performance
P050A - Cold Start Idle Air Control System Performance
MONITOR DESCRIPTION
This monitor will run when the engine is started at an engine coolant temperature of -10 to 50°C (14 to 122°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 at an engine coolant temperature of lower than 50°C (122°F), the ECM measures the accumulated mass air flow at engine idling. If it does not reach the specified level 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 negative battery terminal is disconnected during inspections or repairs, the ISC (Idle Speed Control) learning values are cleared. This DTC cannot be stored with the ISC learning values cleared.
HINT
The 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
WIRING DIAGRAM
Refer to DTC P0102 for the mass air flow meter circuit P0102.
CONFIRMATION DRIVING PATTERN
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON and turn the Techstream on.
3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
4. Turn the ignition switch off and wait for at least 30 seconds.
5. Turn the ignition switch to ON and turn the Techstream on.
6. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp.
7. Check that "Coolant Temp" in the Data List is within the range of -10 to 50°C (14 to 122°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.
10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
11. Read pending DTCs.
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 and ECT / 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 result shows INCOMPLETE or UNKNOWN, idle the engine for 3 minutes, let the engine cool down, and then perform steps [A] through [C] again.
15. If 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
NOTICE:
Inspect the fuses for circuits related to this system before performing the following 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 ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read 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 and ECT / Data List / Short FT #1 and Long FT #1.
(e) Read the values displayed on the Techstream while the engine is idling.
(f) Add together the Short FT #1 and Long FT #1 values to obtain the total Fuel Trim.
Standard:
Total of Short FT #1 and Long FT #1 values is between -20% and 20%.
NG -- CHECK PCV SYSTEM
OK -- Continue to next step.
3. INSPECT THROTTLE BODY
(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.
OK -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
NG -- REPAIR OR REPLACE THROTTLE BODY
4. REPAIR OR REPLACE THROTTLE BODY
(a) Repair or replace throttle body Removal.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
5. CHECK PCV SYSTEM
(a) Start the engine.
(b) Pinch the positive crankcase ventilation (PCV) hose.
(c) Check the engine rpm.
OK:
The engine rpm rises when the PCV hose is pinched.
NG -- REPAIR OR REPLACE PCV SYSTEM
OK -- Continue to next step.
6. CHECK INTAKE SYSTEM
(a) Check the intake system for vacuum leaks Intake System.
OK:
No leak from the intake system.
NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.
7. CHECK AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
(a) 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 -- REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
OK -- Continue to next step.
8. PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE OCV)
(a) Connect the Techstream to the DLC3.
(b) Start the engine.
(c) Turn the Techstream on.
(d) Warm up the engine.
(e) Turn the A/C switch on.
(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Linear (Bank 1).
(g) Check the engine speed while operating the Oil Control Valve (OCV) using the Techstream.
OK:
NG -- CHECK AND REPAIR VVT SYSTEM
OK -- Continue to next step.
9. READ VALUE USING TECHSTREAM (MAF) P0171
OK -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)
10. REPAIR OR REPLACE PCV SYSTEM
(a) Repair or replace the PCV system.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
11. REPAIR OR REPLACE INTAKE SYSTEM
(a) Repair or replace the intake system.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
12. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
(a) Replace the air cleaner filter element sub-assembly.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
13. CHECK AND REPAIR VVT SYSTEM
(a) Check and repair the VVT system.
HINT
Refer to DTC P0011 Inspection Procedure P0011.
NEXT -- Continue to next step.
14. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
NOTICE:
For this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off and wait for at least 30 seconds.
(f) Turn the ignition switch to ON and turn the Techstream on.
(g) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
(h) Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°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 and ECT / Utility / All Readiness.
(l) Input the DTC: P050A.
(m) Check the DTC judgment result.
Result
B -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)
A -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
15. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)
(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 (DTC P050A)
NOTICE:
For this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off and wait for at least 30 seconds.
(f) Turn the ignition switch to ON and turn the Techstream on.
(g) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
(h) Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°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 and ECT / 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) P0171
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
18. REPLACE MASS AIR FLOW METER
(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. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
NOTICE:
For this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off and wait for at least 30 seconds.
(f) Turn the ignition switch to ON and turn the Techstream on.
(g) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
(h) Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°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 and ECT / Utility / All Readiness.
(l) Input the DTC: P050A.
(m) Check the DTC judgment result.
Result
B -- REPLACE ECM Removal
A -- END