P050A
1UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P050A, P050B: Cold Start Idle Air Control System Performance
P050B - Cold Start Ignition Timing 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 (ECT) is between -10°C and 60°C (14°F and 140°F), the ECM calculates the idling intake air amount for 10 seconds, beginning 3 seconds after the engine starts.
When the accumulated value 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 judges 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 ECT is between -10°C and 60°C (14°F and 140°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 sets the DTC and illuminates the MIL 13 seconds after the engine is next started.
NOTICE:
When the negative battery terminal is disconnected during inspection or repairs, the ISC learning values are cleared. The ISC learning must be performed by warming up the engine and idling for 5 minutes with the ECT at 75°C (167°F) or more because DTCs cannot be detected with the ISC learning values cleared.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
P050A:
P050B:
TYPICAL MALFUNCTION THRESHOLDS
P050A:
P050B:
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 at least 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 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 [B].
10. Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.
11. Read the pending DTCs [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 INCOMPLETE or N/A, idle the engine for 3 minutes, let the engine cool down, and then perform steps [A] through [C] again.
15. If the test result is INCOMPLETE or N/A 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. 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 ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A AND/OR P050B)
(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 and P050B 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) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Start the engine.
(e) Enter the following menus: Powertrain / Engine / Data List / A/F Control System / Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2.
(f) Read the values displayed on the Techstream.
(g) 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%.
OK -- CHECK THROTTLE VALVE
NG -- Continue to next step.
3. PERFORM ACTIVE TEST USING TECHSTREAM (VVT-iE SYSTEM)
(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) Engine is idling.
(e) Enter the following menus: Powertrain / Engine / Active Test / Control the VVT-iE Linear (Bank1) or Control the VVT-iE Linear (Bank2) / All Data / VVT-iE Aim Angle #1 and VVT Change Angle #1 or VVT-iE Aim Angle #2 and VVT Change Angle #2.
(f) Perform the Active Test operation with the engine speed at 1500 rpm.
OK:
NG -- CHECK AND REPAIR VVT-iE SYSTEM
OK -- Continue to next step.
4. CHECK VENTILATION HOSE CONNECTIONS
OK:
Ventilation hose is connected correctly and is not damaged.
NG -- REPAIR OR REPLACE VENTILATION HOSE
OK -- Continue to next step.
5. 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.
6. 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.
7. READ VALUE USING TECHSTREAM (MAF SENSOR 1 AND MAF SENSOR 2)
(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 / Primary / Engine Speed, Coolant Temp, MAF Sensor 1 and MAF Sensor 2.
(e) Allow the engine to idle until the ECT reaches 75°C (167°F) or higher.
(f) Read MAF Sensor 1 and MAF Sensor 2 with the engine speed at 2000 rpm.
Standard:
Between 2.4 to 12.8 g/s (shift lever is in N position and A/C is OFF)
NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
8. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
(a) Disconnect the E13 or E22 MAF meter connector.
(b) Disconnect the E1 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. REPLACE MASS AIR FLOW METER (BANK 1 AND/OR BANK 2)
(a) Replace the mass air flow meter Removal.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A AND/OR P050B)
10. CHECK AND REPAIR VVT-iE SYSTEM
(a) Check and repair the VVT-iE system Disassembly.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A AND/OR P050B)
11. REPAIR OR REPLACE VENTILATION HOSE
(a) Repair or replace the ventilation hose Testing and Inspection.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A AND/OR P050B)
12. REPAIR OR REPLACE AIR INDUCTION SYSTEM
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A AND/OR P050B)
13. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A AND/OR P050B)
14. CHECK THROTTLE VALVE
(a) Check for deposits around the throttle valve and throttle valve condition.
OK:
No deposits around throttle valve and throttle valve moves smoothly.
NG -- REPAIR OR REPLACE THROTTLE BODY ASSEMBLY
OK -- Continue to next step.
15. REPLACE ECM
(a) Replace the ECM Removal.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A AND/OR P050B)
16. REPAIR OR REPLACE THROTTLE BODY ASSEMBLY
(a) Repair or replace the throttle body assembly Removal.
NEXT -- Continue to next step.
17. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A AND/OR P050B)
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 engine switch on (IG).
(c) Turn the Techstream on.
(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Switch the ECM from normal mode to check mode using the Techstream Check Mode Procedure.
(f) Start the engine to idle for a minute.
OK:
Stable fast idling.
(g) Read DTCs.
OK:
No DTC output.
NEXT -- END