Last Modified: 05-13-2024 |
6.11:8.1.0 |
Doc ID: RM100000001HT0K |
Model Year Start: 2020 |
Model: Corolla |
Prod Date Range: [03/2019 - 11/2022] |
Title: 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: P0101; Mass Air Flow Circuit Range / Performance Problem; 2020 - 2023 MY Corolla [03/2019 - 11/2022] |
DTC
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P0101
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Mass Air Flow Circuit Range / Performance Problem
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DESCRIPTION
Refer to DTC P0102.
Click here
DTC No.
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Detection Item
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DTC Detection Condition
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Trouble Area
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MIL
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Memory
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Note
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P0101
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Mass Air Flow Circuit Range / Performance Problem
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All of the following conditions continue for more than 10 seconds (2 trip detection logic):
(a) The engine is running.
(b) The engine coolant temperature is 70°C (158°F) or higher.
(c) The throttle position sensor voltage is 0.2 V or higher, and less than 2 V.
(d) Average engine load value ratio is less than 0.85, or higher than 1.15 (varies with estimated engine load).
Average engine load value ratio = Average engine load based on mass air flow meter sub-assembly output / Average engine load estimated from driving conditions
(e) Average air fuel ratio is less than -13%, or higher than 5%
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-
Mass air flow meter sub-assembly
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Intake system
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PCV hose connections
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Comes on
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DTC stored
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DTC for Mexico Models
- Does not apply
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MONITOR DESCRIPTION
The mass air flow meter sub-assembly is a sensor that measures the amount of air flowing through the throttle valve. The ECM uses this information to determine fuel injection timing and to provide an appropriate air fuel ratio. Inside the mass air flow meter sub-assembly, there is a heated platinum wire which is exposed to the flow of intake air. By applying a specific electrical current to the wire, the ECM heats it to a specific temperature. The flow of incoming air cools both the wire and an internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the voltage applied to the mass air flow meter sub-assembly. The voltage level is proportional to the airflow through the sensor, and the ECM uses it to calculate the intake air volume.
The ECM monitors the average engine load value ratio to check the mass air flow meter sub-assembly for malfunctions. The average engine load value ratio is obtained by comparing the average engine load calculated from the mass air flow meter sub-assembly output to the average engine load estimated from the driving conditions, such as the engine speed and the throttle opening angle. If the average engine load value ratio is below the threshold value, the ECM determines that the intake air volume is low, and if the average engine load value ratio is above the threshold value, the ECM determines that the intake air volume is high.
If this is detected in 2 consecutive driving cycles, the MIL is illuminated and a DTC is stored.
MONITOR STRATEGY
Related DTCs
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P0101: Mass air flow meter rationality
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Required Sensors/Components (Main)
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Mass air flow meter sub-assembly
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Required Sensors/Components (Related)
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Crank position sensor
Cam position sensor
Engine coolant temperature sensor
Throttle position sensor
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Frequency of Operation
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Continuous
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Duration
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10 times
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MIL Operation
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2 driving cycles
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Sequence of Operation
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None
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TYPICAL ENABLING CONDITIONS
All of the following conditions are met
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-
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Throttle position voltage
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0.2 V or higher, and less than 2 V
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Time after engine start
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5 seconds or more
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Battery voltage
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10.5 V or higher
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Engine coolant temperature
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70°C (158°F) or higher
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Estimated load
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30% or higher, and less than 80%
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Mass air flow meter circuit fail (P0102, P0103)
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Not detected
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Intake air temperature sensor circuit fail (P0112, P0113)
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Not detected
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Engine coolant temperature sensor circuit fail (P0115, P0117, P0118)
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Not detected
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Crank position sensor circuit fail (P0335)
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Not detected
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Throttle position sensor circuit fail (P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135)
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Not detected
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Canister pressure sensor circuit fail (P0452, P0453)
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Not detected
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Leak detection pump fail (P2401, P2402)
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Not detected
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Evap system vent valve fail (P2419, P2420)
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Not detected
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TYPICAL MALFUNCTION THRESHOLDS
Both of the following conditions are met
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-
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Average engine load value ratio
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Less than 0.85, or higher than 1.15 (varies with estimated engine load)
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Average air fuel ratio
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Less than -13%, or higher than 5%
|
CONFIRMATION DRIVING PATTERN
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Connect the Techstream to the DLC3.
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Turn the ignition switch to ON.
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Turn the Techstream on.
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Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
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Turn the ignition switch off and wait for at least 30 seconds.
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Turn the ignition switch to ON.
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Turn the Techstream on.
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Start the engine and warm it up until the engine coolant temperature reaches 70°C (158°F) or higher [A].
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Drive the vehicle at approximately 80 km/h (50 mph) to 112 km/h (70 mph) for 5 minutes or more [B].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
HINT:
Drive while keeping the engine load as stable as possible.
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Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
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Read the pending DTCs.
HINT:
-
If a pending DTC is output, the system is malfunctioning.
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If a pending DTC is not output, perform the following procedure.
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Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
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Input the DTC: P0101.
-
Check the DTC judgment result.
Techstream Display
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Description
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NORMAL
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-
DTC judgment completed
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System normal
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ABNORMAL
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-
DTC judgment completed
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System abnormal
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INCOMPLETE
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-
DTC judgment not completed
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Perform driving pattern after confirming DTC enabling conditions
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N/A
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-
Unable to perform DTC judgment
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Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
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HINT:
-
If the judgment result shows NORMAL, the system is normal.
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If the judgment result shows ABNORMAL, the system has a malfunction.
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If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [C] again.
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If no pending DTC is output, perform a universal trip and check for permanent DTCs.
Click here
HINT:
-
If a permanent DTC is output, the system is malfunctioning.
-
If no permanent DTC is output, the system is normal.
CAUTION / NOTICE / HINT
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 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.
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CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0101)
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(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 the DTCs.
Powertrain > Engine and ECT > Trouble Codes
Result
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Proceed to
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DTC P0101 is output
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A
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DTC P0101 and other DTCs are output
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B
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HINT:
If any DTCs other than P0101 are output, troubleshoot those DTCs first.
A
|
|
|
(a) Check the intake system for vacuum leaks.
Click here
OK:
No leaks from intake system.
HINT:
Perform "Inspection After Repair" after repairing or replacing the intake system.
Click here
NG |
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REPAIR OR REPLACE INTAKE SYSTEM
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OK
|
|
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3.
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CHECK PCV HOSE CONNECTIONS
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(a) Check the PCV hose connections.
Click here
OK:
PCV valve and hose are connected correctly and are not damaged.
NG |
|
REPAIR OR REPLACE PCV HOSE
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OK
|
|
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4.
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REPLACE MASS AIR FLOW METER SUB-ASSEMBLY
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(a) Replace the mass air flow meter sub-assembly.
Click here
HINT:
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.
Click here
NEXT
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|
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(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear the DTCs.
Powertrain > Engine and ECT > Clear DTCs
(e) Turn the ignition switch off and wait for at least 30 seconds.
NEXT
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|
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6.
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CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
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(a) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(b) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Powertrain > Engine and ECT > Utility
Tester Display
|
All Readiness
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(c) Input the DTC: P0101.
(d) Check the DTC judgment result.
Techstream Display
|
Description
|
NORMAL
|
-
DTC judgment completed
-
System normal
|
ABNORMAL
|
-
DTC judgment completed
-
System abnormal
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INCOMPLETE
|
-
DTC judgment not completed
-
Perform driving pattern after confirming DTC enabling conditions
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N/A
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-
Unable to perform DTC judgment
-
Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
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NEXT |
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END
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