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.


A213258E16
1.563,1.531 1.208,0.375 1.208,0.375 1.063,0.375 true 1.854,1.479 1.854,0.958 1.854,0.958 1.938,0.958 false 4.531,1.646 4.771,2.396 4.771,2.396 4.823,2.396 false 4.313,1.531 3.708,2.146 3.708,2.146 3.708,2.24 false 0.177,0.229 1.01,0.865 0.833,0.635 10 false Temperature Sensor (Thermistor) 1.833,0.635 3.135,0.885 1.302,0.25 10 false Power Transistor 1.99,0.906 4.021,1.146 2.031,0.24 10 false Platinum Hot Wire (Heater) 2.583,1.677 3.656,1.948 1.073,0.271 10 false Output Voltage 4.885,2.344 7.042,2.583 2.156,0.24 10 false Temperature Sensor (Thermistor) 2.635,2.292 4.802,2.458 2.167,0.167 10 false Platinum Hot Wire (Heater)

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

1.

Connect the GTS to the DLC3.

2.

Turn the ignition switch to ON and turn the GTS on.

3.

Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

4.

Turn the ignition switch off and wait for at least 30 seconds.

5.

Turn the ignition switch to ON and turn the GTS on.

6.

Wait for 5 seconds or more.

7.

Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

8.

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.



9.

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

10.

Input the DTC: P0102 or P0103.

11.

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

A298555E36
0.781,4.875 1.854,5.073 1.073,0.198 10 false Battery 1.99,4.26 3.063,4.458 1.073,0.198 10 false FL MAIN 1.969,3.5 3.042,3.698 1.073,0.198 10 false EFI NO. 1 2.979,3.667 4.052,3.865 1.073,0.198 10 false EFI-MAIN 4.073,3.49 5.146,3.688 1.073,0.198 10 false EFI-MAIN 2.833,2.521 2.969,2.719 0.135,0.198 10 false 2 2.823,3.25 2.958,3.448 0.135,0.198 10 false 3 3.615,3.25 3.75,3.448 0.135,0.198 10 false 5 3.625,2.521 3.76,2.719 0.135,0.198 10 false 1 2.802,1.677 3.875,1.875 1.073,0.198 10 false B2 2.802,1.844 5.135,2.042 2.333,0.198 10 false Mass Air Flow Meter Sub-assembly 3.292,0.583 4.365,0.781 1.073,0.198 10 false +B 3.115,0.583 3.25,0.781 0.135,0.198 10 false 3 4.323,0.677 5.396,0.875 1.073,0.198 10 false VG 4.25,1.198 5.323,1.396 1.073,0.198 10 false E2G 4.635,0.677 4.771,0.875 0.135,0.198 10 false 5 4.625,1.198 4.76,1.396 0.135,0.198 10 false 4 5.75,0.594 6.156,0.844 0.406,0.25 10 false 137 5.75,1.115 6.167,1.344 0.417,0.229 10 false 104 5.75,0.781 6.042,0.938 0.292,0.156 10 false B64 5.75,1.313 6.042,1.469 0.292,0.156 10 false B64 5.75,2.604 6.042,2.76 0.292,0.156 10 false A40 5.802,2.417 6.094,2.573 0.292,0.156 10 false 46 6.094,2.604 6.604,2.802 0.51,0.198 10 false MREL 6.073,1.302 6.552,1.563 0.479,0.26 10 false E2G 6.094,0.781 6.406,0.99 0.313,0.208 10 false VG 6.25,5.083 6.76,5.281 0.51,0.198 10 false ECM

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

1.READ OUTPUT DTC (DTC P0102 OR P0103)
a.

Connect the GTS to the DLC3.


b.

Turn the ignition switch to ON.


c.

Turn the GTS on.


d.

Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.


e.

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

2.CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER SUB-ASSEMBLY)

B

5.CHECK HARNESS AND CONNECTOR (SENSOR GROUND)
2.CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER SUB-ASSEMBLY)
A194097C15
0.281,2.021 0.667,2.281 0.385,0.26 1.698,2.458 1.24,3.042 true 0.177,0.073 0.375,0.25 0.198,0.177 10 *a 1.083,3.073 1.458,3.292 0.375,0.219 10 +B 0.396,2.073 0.646,2.271 0.25,0.198 10 B2
*a Front view of wire harness connector
(to Mass Air Flow Meter Sub-assembly)


a.

Disconnect the mass air flow meter sub-assembly connector.


b.

Turn the ignition switch to ON.


c.

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

3.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN RELAY - MASS AIR FLOW METER SUB-ASSEMBLY)

3.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
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

4.INSPECT MASS AIR FLOW METER SUB-ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.INSPECT MASS AIR FLOW METER SUB-ASSEMBLY
a.

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


b.

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


c.

Inspect the function of the mass air flow meter sub-assembly.

i.

Connect the GTS to the DLC3.


ii.

Turn the ignition switch to ON.


iii.

Turn the GTS on.


iv.

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

v.

Start the engine.


vi.

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

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

5.CHECK HARNESS AND CONNECTOR (SENSOR GROUND)
a.

Disconnect the mass air flow meter sub-assembly connector.


b.

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

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

NG

6.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)
6.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
B2-4 (E2G) - B64-104 (E2G) Always Below 1 Ω



Result:
Proceed to
OK
NG



OK

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR