Inspection Procedure

HINT:

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

      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 

   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 of the wire harness side connector and body ground.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      +B (M1-1) - Body ground	9 to 14 V

   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 ECM (VG VOLTAGE) 
   1. Start the engine.
   2. Measure the voltage of the 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 CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      VG (E4-28) - E2G (E4-30)	Engine idling	0.5 to 3.0 V

      Fig 2: Identifying ECM Connector Terminals

      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.
      Fig 3: Identifying MAF Meter Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (M1-3) - VG (E4-28)	Below 1 Ω
      E2G (M1-2) - E2G (E4-30)	Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (M1-3) or VG (E4-28) - Body ground	10 kΩ or higher

      Fig 4: Identifying ECM Connector Terminals

      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. Remove the EFI relay from the engine room relay block.
   2. Disconnect the M1 MAF meter connector.
      Fig 5: Identifying EFI Relay Location

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      +B (M1-1) - Engine room relay block (EFI relay terminal 3)	Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      +B (M1-1) or Engine room relay block (EFI relay terminal 3) - Body ground	10 kΩ or higher

      Fig 6: Identifying MAF Meter Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK : INSPECT ECM POWER SOURCE CIRCUIT 

6. INSPECT ECM (SENSOR GROUND) 
   1. Measure the resistance of the ECM connector and body ground.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      E2G (E4-30) - Body ground	Below 1 Ω

   NG : REPLACE ECM 

   Fig 7: Identifying ECM Connector Terminals

   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 E4 ECM connector.
      Fig 8: Identifying MAF Meter Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (M1-3) - VG (E4-28)	Below 1 Ω
      E2G (M1-2) - E2G (E4-30)	Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connections	Specified Conditions
      VG (M1-3) or VG (E4-28) - Body ground	10 kΩ or higher

      Fig 9: Identifying ECM Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK : REPLACE MASS AIR FLOW METER