Inspection Procedure

HINT:

Read freeze frame data using Techstream. 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 (See FREEZE FRAME DATA ).

1. READ VALUE OF MASS AIR FLOW METER (MAF) 
   1. Connect Techstream to the DLC3.
   2. Start the engine.
   3. Turn the tester on.
   4. Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.
   5. Read the values displayed on the tester.

      Result 

      RESULT REFERENCE 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 E29 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 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      +B (E29-3) - Body ground	9 to 14 V

   4. Reconnect the MAF meter connector.
   Fig 1: Identifying Terminals Of E29 Mass Air Flow (MAF) Meter Connector
   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 according to the value(s) in the table below.

      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 (E5-27) - E2G (E5-26)	Engine idling	0.5 to 3.0 V

   Fig 2: Identifying Terminals Of ECM Connector
   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 E29 MAF meter connector.
   2. Disconnect the E5 ECM connector.
   3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (E29-5) - VG(E5-27)	Below 1 Ω
      E2G (E29-4) - E2G (E5-26)	Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (E29-5) or VG (E5-27) - Body ground	10 kΩ or higher

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.
   Fig 3: Identifying Terminals Of E29 MAF Meter And E5 ECM Connectors
   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 - INTEGRATION RELAY) 
   1. Inspect the EFI No. 2 fuse.
      1. Remove the EFI No. 2 fuse from the engine room No. 2.
      2. Check the EFI No. 2 fuse resistance.

         Standard resistance: 

         Below 1 Ω 

      3. Reinstall the EFI No. 2 fuse.
   2. Disconnect the E29 MAF meter connector.
   3. Remove the integration relay from the engine room No. 2.
   4. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      +B (E29-3) - 2A-8	Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      +B (E29-3) or 2A-8 - Body ground	10 kΩ or higher

      Fig 4: Identifying Terminals Of E29 MAF Meter Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   5. Reconnect the MAF meter connector.
   6. Reinstall the integration relay.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: CHECK ECM POWER SOURCE CIRCUIT 

6. INSPECT ECM (SENSOR GROUND) 
   1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      E2G (E5-26) - Body ground	Below 1 Ω

   Fig 5: Identifying Terminals Of E5 ECM Connector
   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 E29 MAF meter connector.
   2. Disconnect the E5 ECM connector.
   3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (E29-5) - VG(E5-27)	Below 1 Ω
      E2G (E29-4) - E2G (E5-26)	Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      VG (E29-5) or VG (E5-27) - Body ground	10 kΩ or higher

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.
   Fig 6: Identifying Terminals Of E29 MAF Meter And E5 ECM Connectors
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE MASS AIR FLOW METER