P050A
1GR-FE ENGINE CONTROL: SFI SYSTEM: P050A: Cold Start Idle Air Control System Performance
P050A - Cold Start Idle Air Control System Performance
DESCRIPTION
The Electronic Throttle Control System (ETCS) controls the engine idling speed. The ETCS operates the throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the target idling speed.
In addition, the ECM retards the ignition timing and the ETCS increases the intake air amount to quickly increase the catalyst temperature at cold start to reduce emissions.
MONITOR DESCRIPTION
The ECM monitors the intake air amount during idling, and the ignition timing.
When the engine coolant temperature is between -10°C and 50°C (14°F and 122°F), the ECM calculates the idling intake air amount for 10 seconds, beginning 3 seconds after the engine starts.
When the accumulated amount is below the threshold, the ECM interprets this as a malfunction in the Idle Speed Control (ISC) system at cold start.
The ECM also monitors the ignition timing at cold start and determines it to be incorrect when it is advanced to the same value as a warm engine for 5 seconds or more of the 10 second monitoring period.
Example:
P050A is detected when all conditions below are met (2 trip detection logic).
1. The engine coolant temperature is between -10°C and 50°C (14°F and 122°F) when the engine starts.
2. The engine idles for 13 seconds after engine start.
3. The accumulated intake air amount is below the threshold.
The ECM stores the DTC and illuminates the MIL 13 seconds after the engine is next started.
NOTICE:
When the cable is disconnected from the negative battery terminal during inspection or repairs, the ISC learned values are cleared. ISC learning must be performed by warming up the engine and idling for 5 minutes with the engine coolant temperature at 75°C (167°F) or higher because DTCs cannot be detected with the ISC learned values cleared.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
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 [A].
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.
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 and ECT / Trouble Codes [C].
11. Read the 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 NORMAL, the system is normal.
* If the judgment result shows ABNORMAL, the system has a malfunction.
* If the judgment 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.
WIRING DIAGRAM
Refer to DTC P0102 P0102.
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. Freeze frame data records 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.
PROCEDURE
1. CHECK FOR 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 Code.
(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 and ECT / Data List / Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2.
(e) Read the values displayed on the Techstream.
(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 VALVE
(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 WITH MOTOR ASSEMBLY
4. REPAIR OR REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY
(a) Repair or replace the throttle body Removal.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
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 leakage.
OK:
No leakage from air induction system.
NG -- REPAIR OR REPLACE AIR INDUCTION 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:
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 CAMSHAFT TIMING OIL CONTROL VALVE)
(a) Connect the Techstream to the DLC3.
(b) Start the engine and turn the Techstream on.
(c) Warm up the engine.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Linear (Bank 1) or Control the VVT Linear (Bank 2).
(e) Check the engine speed while operating the camshaft timing oil control valve using the Techstream.
OK:
HINT
Refer to "Data List / Active Test" [VVT OCV Duty #1, VVT Change Angle #1, VVT OCV Duty #2 and VVT Change Angle #2] Data List / Active List.
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 and ECT / Data List / All Data / MAF, Coolant Temp and Engine Speed.
(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 13.8 g/sec. and 17.3 g/sec. (shift lever: N; A/C: Off).
OK -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)
10. REPAIR OR REPLACE PCV HOSE
(a) Repair or replace the PCV hose.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
11. REPAIR OR REPLACE AIR INDUCTION SYSTEM
(a) Repair or replace the air induction system.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
12. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
(a) Replace 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:
In 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.
(g) Turn the Techstream on.
(h) Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
(i) Check that the engine coolant temperature is between -10°C and 50°C (14 and 122°F).
(j) Start the engine and warm it up.
(k) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(l) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(m) Input the DTC: P050A.
(n) Check the DTC judgment result.
Result
B -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
A -- Continue to next step.
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:
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 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.
(g) Turn the Techstream on.
(h) Start the engine.
(i) Warm up the engine.
(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)
(a) Disconnect the mass air flow meter connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
(d) Reconnect the mass air flow meter connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM)
OK -- Continue to next step.
18. REPAIR OR REPLACE MASS AIR FLOW METER
(a) Replace the mass air flow meter Removal.
HINT
If the results of the inspections performed in steps 16 and 21 indicated no problem, proceed to the next step without replacing the mass air flow meter.
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 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.
(g) Turn the Techstream on.
(h) Start the engine.
(i) Warm up the engine.
(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