P050A
3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P050A: Cold Start Idle Air Control System Performance
DTC 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 50°C (14 to 122°F). The DTC will be set 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 at lower than 50°C (122°F), the ECM (included in the hybrid vehicle control ECU) measures the accumulated mass air flow at engine idling. If it does not reach the criteria within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is set when the malfunction is detected in consecutive driving cycles (2 trip detection logic).
The electronic throttle control system controls the idle speed. The electronic throttle control system operates the throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the target idle speed.
NOTE: When the negative battery terminal is disconnected during inspections or repairs, the ISC (Idle Speed Control) learning values are cleared. This DTC cannot be set with the ISC learning values cleared.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
INSPECTION PROCEDURE
HINT: When viewed from the rear of the engine assembly, Bank 1 is on the right side and Bank 2 is on the left side.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050A)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Select the following the menu items: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the DTCs.
Result:
HINT: If any DTCs other than P050A are output, troubleshoot those DTCs first.
NG -- GO TO DIAGNOSTIC TROUBLE CODE CHART
OK -- 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 power switch on (IG) and turn the Techstream on.
(c) 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.
(d) Read the values displayed on the Techstream.
(e) 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 -- PERFORM ACTIVE TEST USING TECHSTREAM
OK -- Continue to next step.
3. CHECK THROTTLE BODY
(a) Check for deposits around the throttle valve and throttle valve condition.
OK:
No deposits around throttle valve and throttle valve moves smoothly.
OK -- REPLACE HYBRID VEHICLE CONTROL ECU
NG -- REPAIR OR REPLACE THROTTLE BODY
4. PERFORM ACTIVE TEST USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Start the engine and turn the tester on.
(c) Warm up the engine.
(d) Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the VVT System (Bank 1) or Control the VVT System (Bank 2).
(e) Check the engine speed while operating the oil control valve using the Techstream.
OK:
NG -- CHECK AND REPAIR VVT SYSTEM
OK -- Continue to next step.
5. CHECK PCV SYSTEM
(a) Allow the engine to idle.
(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 HOSE
OK -- Continue to next step.
6. CHECK AIR CLEANER FILTER
(a) Visually check that the air cleaner filter is not excessively contaminated with dirt or oil.
NG -- REPLACE AIR CLEANER FILTER
OK -- Continue to next step.
7. CHECK INTAKE SYSTEM
(a) Check the intake system for vacuum leaks Testing and Inspection.
OK:
No leaks in intake system.
OK -- REPLACE MASS AIR FLOW METER
NG -- REPAIR OR REPLACE INTAKE SYSTEM
8. REPAIR OR REPLACE THROTTLE BODY
(a) Repair or replace the throttle body Components.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
9. REPLACE HYBRID VEHICLE CONTROL ECU
(a) Replace the hybrid vehicle control ECU Components.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
10. CHECK AND REPAIR VVT SYSTEM
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
11. REPAIR OR REPLACE PCV HOSE
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
12. REPLACE AIR CLEANER FILTER
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
13. REPAIR OR REPLACE INTAKE SYSTEM
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
14. REPLACE MASS AIR FLOW METER
(a) Replace the mass air flow meter Components.
NEXT -- Continue to next step.
15. CHECK WHETHER DTC OUTPUT RECURS (DTC P050A)
NOTE: 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 power switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTCs Check Mode Procedure.
(e) Switch the hybrid vehicle control ECU from normal mode to check mode using the Techstream Check Mode Procedure.
(f) Start the engine and let it idle for a minute.
OK:
Stable fast idle.
(g) Read the DTCs.
OK:
No DTC output.
NEXT -- END