2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: P010012,P010017; Mass or Volume Air Flow Sensor "A" Circuit Short to Battery; 2021 - 2022 MY Corolla Corolla HV [04/2020

The mass air flow meter sub-assembly is a sensor that measures the intake air volume. The ECM uses this information to determine the ignition timing and fuel injection duration necessary for an optimal air fuel ratio. Inside the mass air flow meter sub-assembly are a hot wire element and a cold wire element which are exposed to the flow of intake air. The bridge circuit shown in the illustration outputs voltage to transmit information regarding heat loss of the hot wire element caused by air flow. Depending on the air flow, this voltage will change between approximately 0.2 V and 4.9 V. Based on this voltage, the ECM calculates the air flow to determine the ignition timing and fuel injection duration necessary for an optimal air fuel ratio.

When any of these DTCs are stored, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is calculated by the ECM, according to the engine speed and throttle valve position. Fail-safe mode continues until a pass condition is detected.

When these DTCs are output, check the mass air flow rate in the Data List. Enter the following menus: Powertrain / Engine / Data List / Mass Air Flow Sensor.

If the Data List value is normal it may be due to a temporary recovery from the malfunction condition. Check for intermittent problems.

MONITOR DESCRIPTION

If the mass air flow meter sub-assembly is malfunctioning or there is an open or short in the mass air flow meter sub-assembly circuit, the voltage will deviate from the normal operating range. The ECM interprets this deviation as a malfunction in the mass air flow meter sub-assembly circuit, illuminate the MIL and stores a DTC.

When the sensor output voltage remains higher than 4.9 V for 3 seconds or more, the ECM stores a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

All

Case 1

Case 2

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG) [A].
Turn the Techstream on.
Put the engine in Inspection Mode (Maintenance Mode).
Click here
Start the engine.
Idle the engine for 5 seconds [B].
Enter the following menus: Powertrain / Engine / Trouble Codes [C].
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.
With the engine running, during normal driving, increase the vehicle speed to 80 km/h (50 mph) [D].
CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

HINT:

If the engine stops, further depress the accelerator pedal to restart the engine.
With the engine running, depress the accelerator pedal fully to increase the vehicle speed to between 100 and 120 km/h (62 and 75 mph) (engine speed of 4000 rpm or more) and maintain the speed for at least 5 seconds [E].
CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

HINT:

If the engine stops, further depress the accelerator pedal to restart the engine.
Enter the following menus: Powertrain / Engine / Trouble Codes [F].
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.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P010012 or P010017.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions

HINT:

If the judgment result is NORMAL, the system is normal.
If the judgment result is ABNORMAL, the system is malfunctioning.
If the judgment result is INCOMPLETE, perform steps [B] through [F] again.
[A] to [F]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
When clearing the permanent DTCs, do not disconnect the cable from the auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.
Vehicle Control History may be stored in the hybrid vehicle control ECU if the engine is malfunctioning. Certain vehicle condition information is recorded when Vehicle Control History is stored. Reading the vehicle conditions recorded in both the freeze frame data and Vehicle Control History can be useful for troubleshooting.
- for Nickel Metal Hydride Battery: Click here

- for Lithium-ion Battery: Click here

(Select Powertrain in Health Check and then check the time stamp data.)

Click here
If any "Engine Malfunction" Vehicle Control History item has been stored in the hybrid vehicle control ECU, make sure to clear it. However, as all Vehicle Control History items are cleared simultaneously, if any Vehicle Control History items other than "Engine Malfunction" are stored, make sure to perform any troubleshooting for them before clearing Vehicle Control History.
- for Nickel Metal Hydride Battery: Click here

- for Lithium-ion Battery: Click here

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

Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.