Inspection Procedure

HINT:

Read freeze frame data using an intelligent tester. Freeze frame data record 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 INTELLIGENT TESTER (MASS AIR FLOW RATE) 
   1. Connect an intelligent tester to the DLC3.
   2. Start the engine.
   3. Turn the tester ON.
   4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF.
   5. Read the values displayed on the tester.

      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 ((1))	C
      (1) The value must be changed when the throttle valve is open or closed.

   B:  Go to step  6

   C : 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 ON.
   3. Measure the voltage between the terminal of the wire harness side connector and body ground.

      Standard Voltage 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

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

   4. Reconnect the MAF meter connector.
      Fig 1: Inspecting Mass Air Flow Meter (Power Source Voltage)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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 E4 ECM connector.

      HINT:

      The transmission gear selector lever should be in the P or N position and the A/C switch should be turned OFF.

      Standard Voltage 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

      Tester Connections	Conditions	Specified Conditions
      VG (E4-30) - E2G (E4-29)	Engine idling	0.5 to 3.0 V

   Fig 2: Inspecting ECM (VG Voltage)
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK : REPLACE ECM 

   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 E4 ECM connector.
   3. Check the resistance.

      Standard Resistance (Check for open) 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

      Tester Connections	Specified Conditions
      VG (M1-3) - VG (E4-30)	Below 1 Ω
      E2G (M1-2) - E2G (E4-29)

      Standard Resistance (Check for short) 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

      Tester Connections	Specified Conditions
      VG (M1-3) or VG (E4-30)-Body ground	10 kΩ or higher

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.
   Fig 3: Checking Harness And Connector (Mass Air Flow Meter - ECM)
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   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 relay block.
      2. Check the EFI NO. 2 fuse resistance.

         Standard Resistance: 

         Below 1 Ω 

      3. Reinstall the EFI NO. 2 fuse.
   2. Disconnect the M1 MAF meter connector.
   3. Remove the EFI relay from the engine room relay block.
   4. Check the resistance.

      Standard Resistance (Check for open) 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

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

      Standard Resistance (Check for short) 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

      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.
   Fig 4: Checking Harness And Connector (Mass Air Flow Meter - EFI Relay)
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK : CHECK ECM POWER SOURCE CIRCUIT 

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

      Standard Resistance 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

      Tester Connections	Specified Conditions
      E2G (E4-29) - Body ground	Below 1 Ω

   Fig 5: Inspecting ECM (Sensor Ground)
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPLACE ECM 

   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 E4 ECM connector.
   3. Check the resistance.

      Standard Resistance (Check for open) 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

      Tester Connections	Specified Conditions
      VG (M1-3) - VG (E4-30)	Below 1 Ω
      E2G (M1-2) - E2G (E4-29)

      Standard Resistance (Check for short) 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

      Tester Connections	Specified Conditions
      VG (M1 -3) or VG (E4-30) - Body ground	10 kΩ or higher

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.
   Fig 6: Checking Harness And Connector (Mass Air Flow Meter - ECM)
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK : REPLACE MASS AIR FLOW METER