MONITOR DESCRIPTION A monitor will run when the engine is started at an engine coolant temperature of -10 (14°F) or higher, and less than 50°C (122°F). If certain conditions are met, a DTC will be stored after the engine idles for 15 seconds (2 trip detection logic). This DTC is designed to monitor the idle air control at cold start. When the engine is started at an engine coolant temperature of less than 50°C (122°F), the ECM measures the accumulated mass air flow during engine idling. If the accumulated mass air flow does not reach the specified level within 10 seconds, the ECM interprets this as a malfunction, illuminates the MIL and stores this DTC. 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. NOTICE: The idle speed control learned values are cleared by performing learning value reset. Idle speed control learning needs to be performed before this DTC can be stored.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
CONFIRMATION DRIVING PATTERN HINT:
WIRING DIAGRAM Refer to DTC P010012. Click here CAUTION / NOTICE / HINT NOTICE:
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 moving or stationary, 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
(a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine / Trouble Codes. (e) Read the DTCs. Powertrain > Engine > Trouble Codes
HINT: If any DTCs other than P050A00 are output, troubleshoot those DTCs first.
HINT: Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter sub-assembly. (a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Put the engine in Inspection Mode (Maintenance Mode). Powertrain > Hybrid Control > Utility
(e) Start the engine. (f) Enter the following menus: Powertrain / Engine / Data List / Short FT B1S1 and Long FT B1S1. Powertrain > Engine > Data List
(g) Read the values displayed on the Techstream at engine idle. (h) Add the Short FT B1S1 and Long FT B1S1 values to obtain the total fuel trim. Standard:
(a) Check for foreign matter between the throttle valve and housing. If necessary, clean the throttle body with motor assembly. Also, check that the throttle valve moves smoothly. OK: Throttle valve is not contaminated with foreign matter and moves smoothly.
(a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Put the engine in Inspection Mode (Maintenance Mode). Powertrain > Hybrid Control > Utility
(e) Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher. HINT: The A/C switch and all accessories should be off. (f) Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Intake Manifold Absolute Pressure, Coolant Temperature and Engine Independent. Powertrain > Engine > Active Test
(g) Confirm that the value of Data List item Engine Independent is "Operate" then check the value of Intake Manifold Absolute Pressure while performing the Active Test. NOTICE:
OK: The value of Intake Manifold Absolute Pressure changes in response to the EGR step position when the value of Engine Independent is "Operate". Standard:
HINT:
(a) Remove the EGR valve assembly. Click here (b) Check if the EGR valve is stuck open. OK: EGR valve is tightly closed.
(a) Replace the throttle body with motor assembly. Click here HINT: Perform "Inspection After Repair" after replacing the throttle body with motor assembly. Click here
(a) Check the PCV hose connections. (b) Check the PCV valve. Click here OK: PCV hose and PCV valve are connected correctly and are not damaged.
(a) Check the intake system for vacuum leaks. Click here OK: No leaks from intake system.
(a) Visually check that the air cleaner filter element sub-assembly is not excessively contaminated with dirt or oil. OK: The air cleaner filter element sub-assembly is not excessively contaminated with dirt or oil.
(a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Put the engine in Inspection Mode (Maintenance Mode). Powertrain > Hybrid Control > Utility
(e) Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher. HINT: The A/C switch and all accessories should be off. (f) Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Intake Manifold Absolute Pressure, Coolant Temperature and Engine Independent. Powertrain > Engine > Active Test
(g) Confirm that the value of Data List item Engine Independent is "Operate" then check the value of Intake Manifold Absolute Pressure while performing the Active Test. NOTICE:
OK: The value of Intake Manifold Absolute Pressure changes in response to the EGR step position when the value of Engine Independent is "Operate". Standard:
HINT:
(a) Remove the EGR valve assembly. Click here (b) Check if the EGR valve is stuck open. OK: EGR valve is tightly closed.
(a) Operate the VVT system through the Active Test, and check if the VVT system is operating normally. (1) Perform the Active Test, referring to DTC P001100 Procedure (VVT-iE system for intake camshaft). Click here (2) Perform the Active Test, referring to DTC P001400 Procedure (VVT-i system for exhaust camshaft). Click here
(a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Put the engine in Inspection Mode (Maintenance Mode). Powertrain > Hybrid Control > Utility
(e) Start the engine. (f) Enter the following menus: Powertrain / Engine / Data List / Engine Speed, Mass Air Flow Sensor and Coolant Temperature. Powertrain > Engine > Data List
(g) Allow the engine to idle until Coolant Temperature is 75°C (167°F) or higher. (h) Read Mass Air Flow Sensor while maintaining an engine speed of 2500 rpm. HINT: During charge control, the engine speed is set at idle. Therefore, the engine speed will not increase when the accelerator pedal is depressed. In this case, read the Data List after charge control has completed. Standard:
(a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Clear the DTCs. Powertrain > Engine > Clear DTCs(e) Turn the power switch off and wait for at least 30 seconds.
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 power switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature. Powertrain > Engine > Data List
(e) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F). (f) Put the engine in Inspection Mode (Maintenance Mode). Powertrain > Hybrid Control > Utility
(g) Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data. (h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern. (i) Enter the following menus: Powertrain / Engine / Utility / All Readiness. Powertrain > Engine > Utility
(j) Input the DTC: P050A00. (k) Check the DTC judgment result.
(a) Check and repair the VVT system. HINT:
(a) Replace the EGR valve assembly. Click here HINT: Perform "Inspection After Repair" after replacing the EGR valve assembly. Click here
(a) Replace the air cleaner filter element sub-assembly.
(a) Repair or replace the intake system. HINT: Perform "Inspection After Repair" after repairing or replacing the intake system. Click here
(a) Repair or replace PCV valve or hose.
(a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Clear the DTCs. Powertrain > Engine > Clear DTCs(e) Turn the power switch off and wait for at least 30 seconds.
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 power switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature. Powertrain > Engine > Data List
(e) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F). (f) Put the engine in Inspection Mode (Maintenance Mode). Powertrain > Hybrid Control > Utility
(g) Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data. (h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern. (i) Enter the following menus: Powertrain / Engine / Utility / All Readiness. Powertrain > Engine > Utility
(j) Input the DTC: P050A00. (k) Check the DTC judgment result.
(a) Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM. Click here HINT: Repair any problems.
(a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Clear the DTCs. Powertrain > Engine > Clear DTCs(e) Turn the power switch off and wait for at least 30 seconds.
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 power switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature. Powertrain > Engine > Data List
(e) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F). (f) Put the engine in Inspection Mode (Maintenance Mode). Powertrain > Hybrid Control > Utility
(g) Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data. (h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern. (i) Enter the following menus: Powertrain / Engine / Utility / All Readiness. Powertrain > Engine > Utility
(j) Input the DTC: P050A00. (k) Check the DTC judgment result.
(a) Disconnect the mass air flow meter sub-assembly connector. (b) Disconnect the ECM connector. (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:
(a) Replace the mass air flow meter sub-assembly. Click here HINT:
(a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Clear the DTCs. Powertrain > Engine > Clear DTCs(e) Turn the power switch off and wait for at least 30 seconds.
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 power switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature. Powertrain > Engine > Data List
(e) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F). (f) Put the engine in Inspection Mode (Maintenance Mode). Powertrain > Hybrid Control > Utility
(g) Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the Freeze Frame Data. (h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern. (i) Enter the following menus: Powertrain / Engine / Utility / All Readiness. Powertrain > Engine > Utility
(j) Input the DTC: P050A00. (k) Check the DTC judgment result.
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Toyota Avalon (XX50) 2019-2022 Service & Repair Manual > Mass Air Flow Meter: Inspection
INSPECTION PROCEDURE 1. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY (a) Perform a visual check for any foreign matter on the temperature sensor (thermistor) of the mass air flow meter sub-assembly shown in the illustration. OK: There is no foreign matter. If the result is not as specified, replace the ...