2ZR-FE ENGINE CONTROL SFI SYSTEM P0102 Mass Air Flow Circuit Low P0103 Mass Air Flow Circuit High
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 the fuel injection duration 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 wire and internal thermistor. The voltage level is proportional to the airflow through the sensor, and the ECM uses it to calculate the intake air volume.
The circuit is constructed so that the platinum hot wire and the temperature sensor create a bridge circuit, and the power transistor is controlled so that the potentials of A and B remain equal to maintain the predetermined temperature.
- HINT:
-
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.
DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
---|---|---|---|---|---|
P0102 | Mass Air Flow Circuit Low | The mass air flow meter sub-assembly voltage is less than 0.2 V for 3 seconds or more (1 trip detection logic). | ·
Open or short in mass air flow meter sub-assembly circuit ·
Mass air flow meter sub-assembly ·
ECM |
Comes on | DTC stored |
P0103 | Mass Air Flow Circuit High | The mass air flow meter sub-assembly voltage is higher than 4.9 V for 3 seconds or more (1 trip detection logic). | ·
Open or short in mass air flow meter sub-assembly circuit ·
Mass air flow meter sub-assembly ·
ECM |
Comes on | DTC stored |
- HINT:
-
When any of these DTCs are output, check the air flow rate by using the GTS. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.
Mass Air Flow Rate (gm/sec) Malfunction Approximately 0.0 ·Open in mass air flow meter sub-assembly power source circuit
·Open or short in VG circuit
271.0 or more ·Open in E2G circuit
MONITOR DESCRIPTION
If there is a defect or an open or short circuit in the mass air flow meter sub-assembly, the voltage 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 voltage remains less than 0.2 V, or higher than 4.9 V for 3 seconds or more, the ECM stores a DTC.
MONITOR STRATEGY
Frequency of Operation | Continuous |
CONFIRMATION DRIVING PATTERN
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS 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 and turn the GTS on.
Wait for 5 seconds or more.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
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.
GTS 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 |
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 shows INCOMPLETE or N/A, perform the Confirmation Driving Pattern and check the DTC judgment result again.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
- NOTICE:
-
Inspect the fuses for circuits related to this system before performing the following procedure.
- HINT:
-
Read freeze frame data using the GTS. 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
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs.
- Powertrain > Engine and ECT > Trouble Codes
- 50001 234
- Result:
Result Proceed to DTC P0102 is output A DTC P0103 is output B
A
B
*a | Front view of wire harness connector
(to Mass Air Flow Meter Sub-assembly) |
Disconnect the mass air flow meter sub-assembly connector.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Condition Specified Condition B2-3 (+B) - Body ground Ignition switch ON 11 to 14 V
- Result:
Proceed to OK NG
OK
NG
Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition B2-5 (VG) - B64-137 (VG) Always Below 1 Ω B2-4 (E2G) - B64-104 (E2G) Always Below 1 Ω B2-5 (VG) or B64-137 (VG) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Inspect the mass air flow meter sub-assembly, referring to the On-vehicle Inspection for Mass Air Flow Meter.
Click hereEngine / Hybrid System>2ZR-FE ENGINE CONTROL>MASS AIR FLOW METER>ON-VEHICLE INSPECTION
Inspect the mass air flow meter sub-assembly, referring to the Inspection for Mass Air Flow Meter.
Click hereEngine / Hybrid System>2ZR-FE ENGINE CONTROL>MASS AIR FLOW METER>INSPECTION
Inspect the function of the mass air flow meter sub-assembly.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.
- Powertrain > Engine and ECT > Data List
-
Tester Display MAF - 50003 234 3
Start the engine.
Check that the MAF value changes when the engine is raced.
- OK:
The reading changes.
- HINT:
-
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.
-
Click hereEngine / Hybrid System>2ZR-FE ENGINE CONTROL>SFI SYSTEM>INITIALIZATION
- Result:
Proceed to OK NG
OK
NG
Disconnect the mass air flow meter sub-assembly connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition B2-4 (E2G) - Body ground Always Below 1 Ω
- HINT:
-
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.
-
Click hereEngine / Hybrid System>2ZR-FE ENGINE CONTROL>SFI SYSTEM>INITIALIZATION
- Result:
Proceed to OK NG
OK
NG
Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition B2-4 (E2G) - B64-104 (E2G) Always Below 1 Ω
- Result:
Proceed to OK NG
OK
NG