Inspection Procedure

HINT:

Read freeze frame data using the 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.

1. READ VALUE USING TECHSTREAM (MASS AIR FLOW RATE) 
   1. Connect the Techstream to the DLC3.
   2. Start the engine.
   3. Turn the Techstream on.
   4. Enter the following menus: Powertrain / Engine and ECT /Data List / MAF.
   5. Read the values displayed on the Techstream.

      Result 

      RESULT CHART
      
      

      Result (gm/sec.)	Proceed to
      0.0	A
      271.0 or more	B
      Between 1.0 and 270.0*	C
      HINT: *: The value should change when the throttle valve is opened or closed with the engine running.

      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 meter connector.
   2. Turn the ignition switch to ON.
   3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Switch Condition	Specified Condition
      B2-3 (+B) - Body ground	Ignition switch ON	11 to 14 V

   4. Reconnect the mass air flow meter connector.

      NG: Go to step  5

      Fig 1: Identifying Mass Air Flow Meter Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to Next Step 

3. INSPECT MASS AIR FLOW METER 
   1. Inspect output voltage.
      1. Disconnect the mass air flow meter connector.
      2. Apply battery voltage across terminals +B and E2G.
      3. Connect the positive (+) tester probe to terminal VG, and the negative (-) tester probe to terminal E2G.
      4. Measure the voltage according to the value(s) in the table below.

         Standard Voltage 

         TESTER CONNECTION SPECIFIED CONDITION CHART
         
         

         Tester Connection	Condition	Specified Condition
         5 (VG) - 4 (E2G)	Apply battery voltage across terminal +B and E2G	0.2 to 4.9 V

      5. Reconnect the mass air flow meter connector.

         NG: REPLACE MASS AIR FLOW METER  (See REMOVAL )

         Fig 2: Inspecting Mass Air Flow Meter

         Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

         OK: Go to Next Step 

4. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the mass air flow meter meter connector.
   2. Disconnect the ECM connector.
   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      B2-5 (VG) - B29-118 (VG)	Always	Below 1 Ω
      B2-4 (E2G) - B29-116 (E2G)

      Standard Resistance (Check for Short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      B2-5 (VG) or B29-118 (VG) - Body ground	Always	10 kΩ or higher

   4. Reconnect the mass air flow meter meter connector.
   5. Reconnect the ECM connector.

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER ECM) 

      Fig 3: Checking Harness And Connector (Mass Air Flow Meter - ECM)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPLACE ECM  (See REMOVAL )

5. INSPECT FUSE (EFI NO. 1 FUSE) 
   1. Remove the EFI No. 1 fuse from the engine room relay block.
   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      EFI No. 1 fuse	Always	Below 1 Ω

   3. Reinstall the EFI No. 1 fuse. NG

      NG: CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

      Fig 4: Identifying EFI No. 1 Fuse

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

6. CHECK HARNESS AND CONNECTOR (SENSOR GROUND) 
   1. Disconnect the mass air flow meter meter connector.
   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      B2-4 (E2G) - Body ground	Always	Below 1 Ω

   3. Reconnect the mass air flow meter meter connector.

      NG: Go to step 7 

      Fig 5: Identifying Mass Air Flow Meter Meter Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPLACE MASS AIR FLOW METER  (See REMOVAL )

7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the mass air flow meter meter connector.
   2. Disconnect the ECM connector.
   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      B2-5 (VG) - B29-118 (VG)	Always	Below 1 Ω
      B2-4 (E2G) - B29-116 (E2G)

      Standard Resistance (Check for Short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      B2-5 (VG) or B29-118 (VG) - Body ground	Always	10 kΩ or higher

   4. Reconnect the mass air flow meter meter connector.
   5. Reconnect the ECM connector.

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER ECM) 

      Fig 6: Identifying Mass Air Flow Meter Meter Connector And ECM Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPLACE ECM  (See REMOVAL )