Inspection Procedure

HINT:

Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. 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.

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 / All Data / MAF.
   5. Read the values displayed on the Techstream.

      Result 

      RESULT REFERENCE
      
      

      Mass Air Flow Rate (g/sec.)	Proceed to
      0.0	A
      271.0 or more	B
      Between 1.0 and 270.0*	C
      HINT: *: The value must change when the throttle valve is open 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 C3 Mass Air Flow (MAF) meter connector.
   2. Turn the engine switch on (IG).
   3. Measure the voltage according to the value (s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATION
      
      

      Tester Connection	Switch Condition	Specified Condition
      C3-1 (+B) - Body ground	Engine switch on (IG)	11 to 14 V

   NG: Go to Step  5

   Fig 1: Identifying C3 Mass Air Flow Meter Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Go to Next Step 

3. INSPECT MASS AIR FLOW METER 
   1. Remove the Mass Air Flow (MAF) meter (See REMOVAL ).
   2. Inspect the MAF meter.
      1. Measure the voltage according to the value (s) in the table below.

         OK 

         VOLTAGE SPECIFICATION
         
         

         Tester Connection	Condition	Specified Condition
         2 (E2G) - 3 (VG)	Battery voltage applied to terminals 1 (+B) - 2 (E2G) Air blown into the MAF meter	Voltage fluctuates

         NOTE: While using the battery during inspection, do not bring the positive and negative tester probes too close to each other as a short circuit may occur.

   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 C3 MAF meter connector.
   2. Disconnect the C53 ECM connector.
   3. Measure the resistance according to the value (s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      C3-3 (VG) - C53-74 (VG)	Always	Below 1 Ω
      C3-2 (E2G) - C53-75 (E2G)	Always	Below 1 Ω
      C3-3 (VG) or C53-74 (VG) - Body ground	Always	10 kΩ or higher

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 3: Identifying C3 MAF Meter And C53 ECM Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: REPLACE ECM  (See ECM )

5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY) 
   1. Check the EFI NO. 2 fuse.
      1. Remove the EFI NO. 2 fuse from the engine room relay block.
      2. Measure the resistance according to the value (s) in the table below.

         Standard Resistance 

         STANDARD RESISTANCE SPECIFICATION
         
         

         Tester Connection	Condition	Specified Condition
         EFI NO. 2 fuse	Always	Below 1 Ω

      3. Reinstall the EFI NO. 2 fuse.
   2. Disconnect the C3 MAF meter connector.
   3. Remove the integration relay from the engine room relay block.
   4. Measure the resistance according to the value (s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      C3-1 (+B) - 1B-4	Always	Below 1 Ω
      C3-1 (+B) or 1B-4-Body ground	Always	10 kΩ or higher

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 4: Identifying Mass Air Flow Meter And Integration Relay Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: CHECK ECM POWER SOURCE CIRCUIT  (See ECM POWER SOURCE CIRCUIT )

6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the C3 MAF meter connector.
   2. Disconnect the C53 ECM connector.
   3. Measure the resistance according to the value (s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      C3-3 (VG) - C53-74 (VG)	Always	Below 1 Ω
      C3-2 (E2G) - C53-75 (E2G)	Always	Below 1 Ω
      C3-3 (VG) or C53-74 (VG) - Body ground	Always	10 kΩ or higher

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 5: Identifying C3 MAF Meter And C53 ECM Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Go to Next Step 

7. CHECK HARNESS AND CONNECTOR (SENSOR GROUND) 
   1. Disconnect the C3 MAF meter connector.
   2. Measure the resistance according to the value (s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      C3-2 (E2G) - Body ground	Always	Below 1 Ω

   NG: REPLACE ECM  (See ECM )

   Fig 6: Identifying C3 MAF Meter Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: REPLACE MASS AIR FLOW METER  (See REMOVAL )