Inspection Procedure

HINT:

• If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
• 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.

1. READ VALUE OF TECHSTREAM (INTAKE AIR TEMPERATURE) 
   1. Connect Techstream to the DLC3.
   2. Turn the ignition switch to the ON position.
   3. Turn the tester on.
   4. Select the following menu items: Powertrain / Engine and ECT / Data List / All Data / Intake Air.
   5. Read the value displayed on the tester.

      Standard: Same as actual Intake Air Temperature (IAT). 

      Result 

      RESULT REFERENCE
      
      

      Temperature Displayed	Proceed to
      -40°C (-40°F)	A
      140°C (284°F) or higher	B
      Same as actual IAT	C

      HINT:

      • If there is an open circuit, Techstream indicates -40°C (-40°F).
      • If there is a short circuit, Techstream indicates 140°C (284°F) or higher.

   B:  Go to step  4

   C: CHECK FOR INTERMITTENT PROBLEMS 

   A: Go to next step 

2. READ VALUE OF TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS) 
   1. Disconnect the M6 Mass Air Flow (MAF) meter connector.
   Fig 1: Identifying M6 Mass Air Flow Meter Connector
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect terminals THA and E2 of the MAF meter wire harness side connector.
   3. Connect Techstream to the DLC3.
   4. Turn the ignition switch to the ON position.
   5. Turn the tester on.
   6. Select the following menu items: Powertrain / Engine and ECT / Data List / All Data / Intake Air.
   7. Read the value displayed on the tester.

      Standard: 140°C (284°F) or higher 

   8. Reconnect the MAF meter connector.

   OK: REPLACE MASS AIR FLOW METER  (See REMOVAL )

   NG: Go to next step 

3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the M6 MAF meter connector.
   Fig 2: Identifying M6 MAF Meter Connector And E9 ECM Connector
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Disconnect the E9 ECM connector.
   3. Measure the resistance according to the value(s) in the table below.

      Standard resistance: Check for open 

      RESISTANCE SPECIFIED CONDITIONS
      
      

      Tester Connection	Specified Condition
      THA (E9-22) - THA (M6-1)	Below 1 Ω
      E2 (E9-28) - E2 (M6-2)	Below 1 Ω

      Check for short 

      RESISTANCE SPECIFIED CONDITIONS
      
      

      Tester Connection	Specified Condition
      THA (E9-22) or THA (M6-1) - Body ground	10 kΩ or higher
      E2 (E9-28) or E2 (M6-2) - Body ground	10 kΩ or higher

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER ECM) 

   NG: REPLACE ECM  (See REMOVAL )

4. READ VALUE OF TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS) 
   1. Disconnect the M6 MAF meter connector.
   Fig 3: Identifying MAF Meter Connector Terminal
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect Techstream to the DLC3.
   3. Turn the ignition switch to the ON position.
   4. Turn the tester on.
   5. Select the following menu items: Powertrain / Engine and ECT / Data List / All Data / Intake Air.
   6. Read the value displayed on the tester.

      Standard: -40°C (-40°F) 

   7. Reconnect the MAF meter connector.

   OK: REPLACE MASS AIR FLOW METER 

   NG: Go to next step 

5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the M6 MAF meter connector.
   Fig 4: Identifying M6 MAF Meter Connector And E9 ECM Connector
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Disconnect the E9 ECM connector.
   3. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE SPECIFIED CONDITIONS
      
      

      Tester Connection	Specified Condition
      THA (E9-22) or THA (M6-1) - Body ground	10 kΩ or higher

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER ECM) 

   NG: REPLACE ECM  (See REMOVAL )