Inspection Procedure

HINT:

• If different DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may be open.
• Read freeze frame data using the hand-held tester or the OBDII scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful to determine whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time the malfunction occurred.

1. Connect OBD II scan tool or hand-held tester, and read value of intake air temperature. 

   PREPARATION: 

   1. Connect the OBD II scan tool or hand-held tester to the DLC3.
   2. Turn the ignition switch ON and push the OBD II scan tool or hand-held tester main switch ON.
   3. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR".

   CHECK: 

   Read the temperature value on the OBD II scan tool or hand-held tester.

   OK: 

   Same value as the actual intake air temperature. 

   RESULT: 

   TEMPERATURE DISPLAYED SPECIFICATION
   
   

   Temperature Displayed	Proceed to
   -40 °C (-40 °F)	A
   140°C (284°F) or more	B
   OK (Same as present temperature)	C

   HINT:

   • If there is an open circuit, the hand-held tester or the OBD II scan tool indicates -40°C (-40°F).
   • If there is a short circuit, the hand-held tester or the OBD II scan tool indicates 140°C (284°F) or more.
   1. B: Go to step   4 . 
   2. C: Check for intermittent problems (See  PRE-CHECK  ). 
   3. A: Go to next step. 
2. Check for open in harness or ECM. 

   PREPARATION: 

   1. Disconnect the M1 mass air flow meter connector.
   2. Connect terminals THA and E2 of the mass air flow meter wire harness side connector.
   3. Turn the ignition switch ON.
   4. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR".
      Fig 1: Disconnecting M1 Mass Air Flow Meter Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   CHECK: 

   Read the temperature value on the OBD II scan tool or hand held tester.

   OK: 

   Temperature value: 140°C (284°F) or more 

   Fig 2: Connecting Terminals THA And E2 Of Mass Air Flow Meter Wire Harness Side Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Confirm good connection at sensor. If OK, replace mass air flow meter. 

   NG: Go to next step. 

3. Check for open in harness or ECM. 

   PREPARATION: 

   1. Disconnect the M1 mass air flow meter connector.
   2. Connect terminals THA and E2 of the E6 ECM connector.

      HINT:

      Before checking, do a visual and contact pressure check for the ECM connector.

   3. Turn the ignition switch ON.
   4. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR".
      Fig 3: Disconnecting M1 Mass Air Flow Meter Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   CHECK: 

   Read the temperature value on the OBD II scan tool or hand held tester.

   OK: 

   Temperature value: 140°C (284°F) or more 

   Fig 4: Connecting Terminals THA And E2 Of E6 ECM Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Repair or replace harness or connector. 

   NG: Confirm good connection at ECM. If OK, replace ECM (See  COMPONENTS  ). 

4. Check for short in harness and ECM. 

   PREPARATION: 

   1. Disconnect the M1 mass air flow meter connector.
   2. Turn the ignition switch ON.
   3. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR".

   CHECK: 

   Read the temperature value on the OBD II scan tool or hand held tester.

   OK: 

   Temperature value: -40°C (-40°F) 

   Fig 5: Disconnecting M1 Mass Air Flow Meter Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Replace mass air flow meter. 

   NG: Go to next step. 

5. Check for short in harness or ECM. 

   PREPARATION: 

   1. Disconnect the E6 ECM connector.
   2. Disconnect the mass air flow meter connector.
   3. Turn the ignition switch ON.
   4. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR.
      Fig 6: Disconnecting Mass Air Flow Meter Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   CHECK: 

   Read the temperature value on the OBD II scan tool or hand held tester.

   OK: 

   Temperature value: -40°C (-40°F) 

   Fig 7: Disconnecting E6 ECM Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Repair or replace harness or connector. 

   NG: Replace ECM (See  COMPONENTS  ).