Inspection Procedure

HINT:

Read freeze frame data using the intelligent tester. 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 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. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF.
   5. Read the values displayed on the tester.

      Result 

      RESULT CHART
      
      

      Mass Air Flow Rate (gm/s)	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 to the ON position.
   3. Measure the voltage between the terminal of the wire harness side connector and body ground.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      +B (M1-3) - Body ground	9 to 14 V

   4. Reconnect the MAF meter connector.

   NG: Go to step  5

   Fig 1: Identifying MAF Meter Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Go to Next Step 

3. INSPECT ECM (VG VOLTAGE) 
   1. Start the engine.
   2. Measure the voltage between the terminals of the E8 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
      
      

      Tester Connection	Condition	Specified Condition
      VG (E8-30) - E2G (E8-29)	Engine idling	0.5 to 3.0 V

   OK: REPLACE ECM  (See REMOVAL  )

   Fig 2: Identifying ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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 E8 ECM connector.
   3. Measure the resistance.

      Standard resistance : 

      Check for open 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      VG (M1-5) - VG (E8-30)	Below 1 Ω
      E2G (M1-4) - E2G (E8-29)	Below 1 Ω

      Check for short 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      VG (M1-5) or VG (E8-30) - 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: Identifying MAF Meter And ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: REPLACE MASS AIR FLOW METER  (See REMOVAL  )

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 fusible link.
      2. Measure 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 MAIN relay from the engine room R/B.
   4. Measure the resistance between the terminals.

      Standard resistance: 

      Check for open 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

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

      Check for short 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      +B (M1-3) or Engine room R/B EFI MAIN relay terminal 3 - Body ground	10 MΩ or higher

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

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 4: Identifying MAF Meter And EFI Main Relay Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

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

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      E2G (E8-29) - Body ground	Below 1 Ω

   NG: REPLACE ECM  (See REMOVAL  )

   Fig 5: Identifying ECM Connector Terminal

   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 E8 ECM connector.
   3. Measure the resistance.

      Standard resistance: 

      Check for open 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      VG (M1-5) - VG (E8-30)	Below 1 Ω.
      E2G (M1-4) - E2G (E8-29)	Below 1 Ω

      Check for short 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      VG (M1-5) or VG (E8-30) - 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: Identifying MAF Meter And ECM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: REPLACE MASS AIR FLOW METER  (See REMOVAL  )