Inspection Procedure

HINT:

Read freeze frame data using 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 be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction (See FREEZE FRAME DATA ).

1. READ VALUE OF MASS AIR FLOW METER (MAF) 
   1. Connect Techstream to the DLC3.
   2. Start the engine.
   3. Turn the tester on.
   4. Enter the following menus: Powertrain / Engine / Data List / All Data / MAF.
   5. Read the values displayed on the tester.

      Result 

      RESULT CHART
      
      

      Mass Air Flow Rate (gm/s)	Proceed to
      0.0	A
      271.0 or more	B
      Between 1.0 and 270.0 ((1))	C
      (1) The value must change when the throttle valve is open or closed.

   B:  Go to step  6

   C : CHECK FOR INTERMITTENT PROBLEMS  (See CHECK FOR INTERMITTENT PROBLEMS )

   A: Go to next step 

2. INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE) 
   1. Disconnect the mass air flow (MAF) meter connector.
   2. Turn the ignition switch on (IG).
   3. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      +B (B10-3) - Body ground	9 to 14 V

   4. Reconnect the MAF meter connector.

   NG:  Go to step  5

   Fig 1: Identifying MAF Meter Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Go to next step 

3. INSPECT MASS AIR FLOW METER (VG VOLTAGE) 
   1. Inspect the output voltage.
      1. Apply battery voltage across terminals +B and E2G.
      2. Connect the positive (+) tester probe to terminal VG, and the negative (-) tester probe to terminal E2G.
      3. Measure the voltage between the terminals.

         Standard voltage 

         TESTER CONNECTION SPECIFIED CONDITION CHART
         
         

         Tester Connection	Specified Condition
         5 (VG) - 4 (E2G)	0.2 to 4.9 V

   NG: REPLACE MASS AIR FLOW METER 

   Fig 2: Identifying Mass Air Flow Meter Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Go to next step 

4. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the MAF meter connector.
   2. Disconnect the ECM connector.
   3. Measure the resistance between the terminals.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (B50-72) - VG (B10-5)	Below 1 Ω
      E2G (B50-73) - E2G (B10-4)	Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (B50-72) or VG (B10-5) - Body ground	10 kΩ or higher
      E2G (B50-73) or E2G (B10-4) - Body ground	10 kΩ or higher

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 3: Identifying MAF Meter Connector And ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK : REPLACE ECM  (See ECM )

5. INSPECT FUSE (EFI NO. 2) 
   1. Remove the EFI No. 2 fuse from the engine room R/B.
   2. Measure the EFI No. 2 fuse resistance.

      Standard resistance: 

      Below 1Ω 

   3. Reinstall the EFI No. 2 fuse.

   NG: REPLACE FUSE (EFI NO. 2 FUSE) 

   Fig 4: Identifying EFI No. 2 Fuse

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK : REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI RELAY - MASS AIR FLOW METER) 

6. CHECK HARNESS AND CONNECTOR (SENSOR GROUND) 
   1. Disconnect the MAF meter connector.
   2. Measure the resistance between the terminals.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      E2G (B10-4) - Body ground	Below 1 Ω

   3. Reconnect the MAF meter connector.

   OK : REPLACE MASS AIR FLOW METER 

   Fig 5: Identifying MAF Meter Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: Go to next step 

7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the MAF meter connector.
   2. Disconnect the ECM connector.
   3. Measure the resistance between the terminals.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (B50-72) - VG (B10-5)	Below 1 Ω
      E2G (B50-73) - E2G (B10-4)	Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (B50-72) or VG (B10-5) - Body ground	10 kΩ or higher
      E2G (B50-73) or E2G (B10-4) - Body ground	10 kΩ or higher

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 6: Identifying MAF Meter Connector And ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK : REPLACE ECM  (See ECM )