- DTC judgment completed
- System normal
| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM100000001HT0Q |
| Model Year Start: 2020 | Model: Corolla | Prod Date Range: [03/2019 - 11/2022] |
| Title: 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: P0102,P0103; Mass Air Flow Circuit Low; 2020 - 2023 MY Corolla [03/2019 - 11/2022] | ||
|
DTC |
P0102 |
Mass Air Flow Circuit Low |
|
DTC |
P0103 |
Mass Air Flow Circuit High |
DESCRIPTION
The mass air flow meter sub-assembly is a sensor that measures the intake air volume using the following built-in components:
- By-pass passage (allows some of the intake air to flow past a silicon chip sensor)
- Silicon chip sensor (uses a heater control bridge circuit and temperature sensor bridge circuit to detect the difference in the temperature of the intake air that passes the sensors positioned before and after the heater).
- Control circuit (converts the difference in temperature into a pulse signal and performs correction)
Intake air flows over the temperature sensor (before heater), the heater, and then the temperature sensor (after heater) on the silicon chip sensor in the by-pass passage. As the intake air is warmed up when it is exposed to the heater, the temperature of the intake air flowing over the temperature sensor (after heater) is higher than that over the temperature sensor (before heater). The difference in temperature of the intake air at each temperature sensor varies depending on the velocity of the intake air that flows over the silicon chip sensor. The temperature sensor bridge circuit detects the difference in temperature and the control circuit converts it into a pulse signal and outputs it to the ECM. When the temperature detected by the temperature sensor (before heater) is higher than that detected by the temperature sensor (after heater), backflow of the intake air is detected.
The ECM calculates the intake air amount based on the pulse signal received from the mass air flow meter sub-assembly, and uses it to determine the fuel injection duration necessary for an optimal air-fuel ratio.
The heater control bridge circuit includes temperature sensors and power transistor, and maintains the heater temperature at a specific temperature.
HINT:
When DTCs is stored, the ECM enters fail-safe mode. During fail-safe mode, the ECM calculates the fuel injection duration based on the engine speed and throttle valve angle. Fail-safe mode continues until a pass condition is detected.
|
*a |
Temperature Sensor (Before Heater) |
*b |
Temperature Sensor (After Heater) |
|
*c |
Heater |
*d |
Silicon Chip Sensor |
|
*e |
Air Flow |
- |
- |
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
MIL |
Memory |
Note |
|---|---|---|---|---|---|---|
|
P0102 |
Mass Air Flow Circuit Low |
The mass air flow meter sub-assembly output frequency is less than 0.1 kHz for 3 seconds (1 trip detection logic) |
|
Comes on |
DTC stored |
DTC for Mexico Models - Applies |
|
P0103 |
Mass Air Flow Circuit High |
The mass air flow meter sub-assembly output frequency is higher than 9.8 kHz for 3 seconds. (1 trip detection logic) |
|
Comes on |
DTC stored |
DTC for Mexico Models - Applies |
MONITOR DESCRIPTION
If there is a defect or an open or short circuit in the mass air flow meter sub-assembly, the frequency level deviates from the normal operating range. The ECM interprets this deviation as a malfunction in the mass air flow meter sub-assembly circuit and stores a DTC.
Example:
When the sensor output frequency remains less than 0.1 kHz, or higher than 9.8 kHz for 3 seconds, the ECM stores a DTC.
MONITOR STRATEGY
|
Related DTCs |
P0102: Mass air flow range check (low frequency) P0103: Mass air flow range check (high frequency) |
|
Required Sensors/Components (Main) |
Mass air flow meter sub-assembly |
|
Required Sensors/Components (Related) |
Crank position sensor |
|
Frequency of Operation |
Continuous |
|
Duration |
3 seconds |
|
MIL Operation |
Immediate |
|
Sequence of Operation |
None |
TYPICAL ENABLING CONDITIONS
|
Monitor runs whenever the following DTCs are not stored |
None |
|
Battery voltage |
8 V or higher |
|
Ignition switch |
ON |
|
Time after ignition switch off to ON |
0.5 seconds or more |
|
Starter |
Off |
|
Time after starter on to off |
0.5 seconds or more |
TYPICAL MALFUNCTION THRESHOLDS
P0102
|
Mass air flow meter output frequency |
Less than 0.1 kHz |
P0103
|
Mass air flow meter output frequency |
Higher than 9.8 kHz |
CONFIRMATION DRIVING PATTERN
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
- Turn the ignition switch off and wait for at least 30 seconds.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Wait 5 seconds or more.
- Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
- Turn the Techstream on.
-
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 and ECT / Utility / All Readiness.
- Input the DTC: P0102 or P0103.
-
Check the DTC judgment result.
Techstream Display
Description
NORMAL
ABNORMAL
- DTC judgment completed
- System abnormal
INCOMPLETE
- DTC judgment not completed
- Perform driving pattern after confirming DTC enabling conditions
N/A
- Unable to perform DTC judgment
- Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
HINT:
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
-
If the judgment result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs.
Click here
![2020 - 2022 MY Corolla [03/2019 - 09/2022]; 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif)
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
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. |
CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER) |
|
*a |
Front view of wire harness connector (to Mass Air Flow Meter Sub-assembly) |
(a) Disconnect the mass air flow meter sub-assembly.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Switch Condition |
Specified Condition |
|---|---|---|
|
C26-3 (VCC) - C26-2 (E2G) |
Ignition switch ON |
4.8 to 5.2 V |
|
C26-1 (FG) - C26-2 (E2G) |
Ignition switch ON |
4.8 to 5.2 V |
| NG |
|
|
|
2. |
REPLACE MASS AIR FLOW METER SUB-ASSEMBLY |
(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
|
|
3. |
CLEAR DTC |
(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.
|
|
4. |
CHECK WHETHER DTC OUTPUT RECURS (DTC P0102 OR P0103) |
(a) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
(b) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(c) Read the DTCs.
Powertrain > Engine and ECT > Trouble Codes
|
Result |
Proceed to |
|---|---|
|
DTCs are not output |
A |
|
DTC P0102 and/or P0103 is output |
B |
| A |
|
END |
| B |
|
REPLACE ECM
|
|
5. |
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) |
(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:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
C26-1 (FG) - C77-137 (VG) |
Always |
Below 1 Ω |
|
C26-2 (E2G) - C77-104 (E2G) |
Always |
Below 1 Ω |
|
C26-3 (VCC) - C77-103 (VCVG) |
Always |
Below 1 Ω |
|
C26-1 (FG) or C77-137 (VG) - Body ground and other terminals |
Always |
10 kΩ or higher |
|
C26-3 (VCC) or C77-103 (VCVG) - Body ground and other terminals |
Always |
10 kΩ or higher |
| OK |
|
REPLACE ECM
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|