SFI SYSTEM(w/ Canister Pump Module), Diagnostic DTC:P010012, P010014, P010A12, P010A14

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.

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

CONFIRMATION DRIVING PATTERN

1. Connect the GTS to the DLC3.

2. Turn the engine switch on (IG).

3. Turn the GTS on.

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

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

6. Turn the engine switch on (IG).

7. Turn the GTS on.

8. Wait 5 seconds or more [A].

9. Enter the following menus: Powertrain / Engine / Trouble Codes [B].

10. 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.

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

12. Input the DTC: P010012, P010014, P010A12 or P010A14.

13. 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

    Tech Tips

    
    

    • If the judgment result is NORMAL, the system is normal.

    • If the judgment result is ABNORMAL, the system has a malfunction.

    • If the judgment result is INCOMPLETE, perform steps [A] through [B] again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK HARNESS AND CONNECTOR

   Tech Tips

   Make sure that the connector is properly connected. If it is not, securely connect it and check for DTCs again.

   
   

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

   2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition D17-3 (VCCR) - D17-2 (E2GR) Engine switch on (IG) 4.8 to 5.2 V D17-1 (FGR) - D17-2 (E2GR) Engine switch on (IG) 4.8 to 5.2 V D16-3 (VCC) - D16-2 (E2G) Engine switch on (IG) 4.8 to 5.2 V D16-1 (FG) - D16-2 (E2G) Engine switch on (IG) 4.8 to 5.2 V

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition D17-3(VCCR) - D17-1(FGR) Engine switch off 2.09 to 2.31 kΩ D16-3(VCC) - D16-1(FG) Engine switch off 2.09 to 2.31 kΩ D17-2(E2GR) - Body ground Always Below 1 Ω D16-2(E2G) - Body ground Always Below 1 Ω

      Tech Tips

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

      Click here

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Click here

   NG

2. 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 D17-3 (VCCR) - D1-107 (VCVG) Always Below 1 Ω D17-1 (FGR) - D1-82 (VG) Always Below 1 Ω D17-2 (E2GR) - D1-84 (E2G) Always Below 1 Ω D16-3 (VCC) - D1-107 (VCVG) Always Below 1 Ω D16-1 (FG) - D1-80 (VG2) Always Below 1 Ω D16-2 (E2G) - D1-84 (E2G) Always Below 1 Ω D17-3 (VCCR) or D1-107 (VCVG) - Body ground and other terminals Always 10 kΩ or higher D17-1 (FGR) or D1-82 (VG) - Body ground and other terminals Always 10 kΩ or higher D16-3 (VCC) or D1-107 (VCVG) - Body ground and other terminals Always 10 kΩ or higher D16-1 (FG) or D1-80 (VG2) - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE ECM Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR