СИСТЕМА SFI (для моделей без системы РОГ), Diagnostic DTC:P0102, P0103

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.

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, the ECM stores a DTC.

MONITOR STRATEGY

CONFIRMATION DRIVING PATTERN

1. Connect the GTS to the DLC3.

2. Turn the power switch on (IG) and turn the GTS on.

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

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

5. Turn the power switch on (IG) and turn the GTS on.

6. Wait 5 seconds or more.

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

8. Read the pending DTCs.

   Tech Tips

   
   

   • 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

    Tech Tips

    
    

    • 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

INSPECTION PROCEDURE

PROCEDURE

1. READ OUTPUT DTC (DTC P0102 OR P0103)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the GTS on.

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

   5. Read the DTCs.

      Result

      Result	Proceed to
      DTC P0102 is output	A
      DTC P0103 is output	B

   
   

   B

   CHECK HARNESS AND CONNECTOR (SENSOR GROUND) Click here

   A

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

   
   
   1. 

      Text in Illustration

      *a	Front view of wire harness connector (to Mass Air Flow Meter Sub-assembly)

      Disconnect the mass air flow meter sub-assembly connector.

   2. Turn the power switch on (IG).

   3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition F39-3 (+B) - Body ground Power switch on (IG) 11 to 14 V

   
   

   NG

   CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - MASS AIR FLOW METER) Click here

   OK

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

   
   

   1. Disconnect the mass air flow meter sub-assembly connector.

   2. Disconnect the ECM connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition F39-5 (VG) - F70-91 (VG) Always Below 1 Ω F39-4 (E2G) - F70-92 (E2G) Always Below 1 Ω F39-5 (VG) or F70-91 (VG) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

4. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY

   
   

   1. Inspect the mass air flow meter sub-assembly, referring to the On-vehicle Inspection for Mass Air Flow Meter Click here.

   2. Inspect the mass air flow meter sub-assembly, referring to the Inspection for Mass Air Flow Meter Click here.

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

      
      

      1. Connect the GTS to the DLC3.

      2. Turn the power switch on (IG).

      3. Turn the GTS on.

      4. Put the engine in inspection mode (maintenance mode) Click here.

      5. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.

      6. Start the engine.

      7. Check that the MAF value changes when the engine is raced.

         OK
         The reading changes.

         Tech Tips

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

   
   

   NG

   REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Click here

   OK

   REPLACE ECM Click here

5. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - MASS AIR FLOW METER)

   
   

   1. Disconnect the mass air flow meter sub-assembly connector.

   2. Remove the No. 1 integration relay from the No. 1 engine room relay block assembly.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition 1E-15- F39-3 (+B) Always Below 1 Ω 1E-15 or F39-3 (+B) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   REPLACE NO.1 INTEGRATION RELAY

6. CHECK HARNESS AND CONNECTOR (SENSOR GROUND)

   
   

   1. Disconnect the mass air flow meter sub-assembly connector.

   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition F39-4 (E2G) - Body ground Always Below 1 Ω

      Tech Tips

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

   
   

   NG

   CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) Click here

   OK

   REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Click here

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

   
   

   1. Disconnect the mass air flow meter sub-assembly connector.

   2. Disconnect the ECM connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition F39-4 (E2G) - F70-92 (E2G) Always Below 1 Ω

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   REPLACE ECM Click here