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 DATA LIST (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/MAR
   5. Read the values displayed on the Techstream.

      Result 

      RESULT CHART
      
      

      Mass Air Flow Rate (g/sec)	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 M1 Mass Air Flow (MAF) meter connector.
   2. Turn the ignition switch to ON.
   3. Measure the voltage between the terminal of the wire harness side connector and body ground.

      Standard Voltage 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Specified Conditions
      +B (M1-1) - Body ground	9 to 14 V

      Fig 1: Identifying MAF Meter Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   4. Reconnect the MAF meter connector.

      NG:  Go to step  5

      OK: Go to next step 

3. INSPECT ECM (VG VOLTAGE) 
   1. Start the engine.
   2. Measure the voltage between the terminals of the ECM connector.

      HINT:

      The shift lever should be on P or N (for A/T), or neutral (for M/T), and the A/C switch should be turned OFF.

      Fig 2: Inspecting ECM (VG Voltage)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Voltage 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Engine Conditions	Specified Conditions
      VG (ES-28) - E2G (E5-30)	Engine idling	0.5 to 3.0 V

      OK: REPLACE ECM  (See REMOVAL  )

      NG: Go to next step 

4. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the M1 MAF meter connector.
   2. Disconnect the E5 ECM connector.
   3. Check the resistance.

      Standard Resistance (Check for open) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Specified Conditions
      VG (M1-3) - VG (E5-28)	Below 1 Ω
      E2G (M1-2) - E2G (E5-30)	Below 1 Ω

      Standard Resistance (Check for short) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Specified Conditions
      VG (M1-3) or VG (E5-28) - 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: Disconnecting E5 ECM Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPLACE MASS AIR FLOW METER 

5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - EFI RELAY) 
   1. Inspect the EFI No. 2 fuse.
      1. Remove the EFI No. 2 fuse from the engine room R/B.
      2. Check the EFI No. 2 fuse resistance.

         Standard Resistance: 

         Below 1 Ω 

      3. Reinstall the EFI No. 2 fuse.
   2. Remove the EFI relay from the engine room R/B.
   3. Disconnect the M1 MAF meter connector.
   4. Check the resistance.
      Fig 4: Checking Harness And Connector (Mass Air Flow Meter - EFI Relay)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance (Check for open) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Specified Conditions
      +B (M1-1) - EFI relay (3)	Below 1 Ω

      Standard Resistance (Check for short) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Specified Conditions
      +B (M1-1) or EFI relay (3) - Body ground	10 kΩ or higher

   5. Reconnect the MAF meter connector.
   6. Reinstall the EFI relay.

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

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

6. INSPECT ECM (SENSOR GROUND) 
   1. Check the resistance.

      Standard Resistance 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Specified Conditions
      E2G (E5-30) - Body ground	Below 1 Ω

      NG: REPLACE ECM  (See REMOVAL  )

      Fig 5: Inspecting ECM (Sensor Ground)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the M1 MAF meter connector.
   2. Disconnect the E5 ECM connector.
   3. Check the resistance.

      Standard Resistance (Check for open) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Specified Conditions
      VG (M1-3) - VG(E5-28)	Below 1 Ω
      E2G (M1-2) - E2G(E5-30)	Below 1 Ω

      Standard Resistance (Check for short) 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Specified Conditions
      VG (M1-3) or VG (E5-28) - 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: Checking Harness And Connector (Mass Air Flow Meter - ECM)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPLACE MASS AIR FLOW METER