Inspection Procedure

HINT:

• If different DTCs that are related to different systems are output simultaneously while terminal E2 is used as a ground terminal, terminal E2 may be open.
• Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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. Connect hand-held tester or OBD II scan tool, and read value of intake air temperature. 

   PREPARATION: 

   1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
   2. Turn the ignition switch ON. Push the hand-held tester or OBD II scan tool main switch ON.
   3. On the hand-held tester or OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.

   CHECK: 

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

   OK: 

   Same value as the actual air intake temperature. 

   HINT:

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

   PREPARATION: 

   1. Disconnect the MAF meter connector.
   2. Connect the terminals THA and E2 of the MAF meter wire harness side connector.
   3. Connect the hand-held tester or the OBD II scan tool to the DLC3.
   4. Turn the ignition switch ON.
   5. Push the hand-held tester or OBD II scan tool main switch ON.
      Fig 1: Checking For Open Harness Or ECM

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   6. On the hand-held tester or OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.

   CHECK: 

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

   OK: 

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

   1. OK : Confirm good connection at sensor. If OK, replace MAF meter. 
   2. NG : Go to next step. 
3. Check for open in harness or ECM. 

   PREPARATION: 

   1. Disconnect the MAF meter connector.
   2. Connect terminals THA and E2 of the ECM connector.

      HINT:

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

   3. Connect the hand-held tester or the OBD II scan tool to the DLC3.
   4. Turn the ignition switch ON.
   5. Push the hand-held tester or OBD II scan tool main switch ON.
   6. On the hand-held tester or OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.

   CHECK: 

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

   OK: 

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

   Fig 2: Checking For Open Harness Or ECM And Locating THA And E2 Connector Terminals Of ECM

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK : Open in harness between terminals E2 or THA, repair or replace harness. 
   2. NG : Confirm good connection at ECM. If OK, replace ECM (see  COMPONENTS  ).  
4. Check for short in harness and ECM. 

   PREPARATION: 

   1. Disconnect the MAF meter connector.
   2. Connect the hand-held tester or the OBD II scan tool to the DLC3.
   3. Turn the ignition switch ON.
   4. Push the hand-held tester or OBD II scan tool main switch ON.
   5. On the hand-held tester or OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
      Fig 3: Checking For Short In Harness And ECM

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   CHECK: 

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

   OK: 

   Temperature value: -40°C (-40°F) 

   1. OK : Replace MAF meter. 
   2. NG : Go to next step. 
5. Check for short in harness or ECM. 

   PREPARATION: 

   1. Disconnect the E6 ECM connector.
   2. Connect the hand-held tester or the OBD II scan tool to the DLC3.

      HINT:

      The MAF meter connector is disconnected.

   3. Turn the ignition switch ON.
   4. Push the hand-held tester or OBD II scan tool main switch ON.
   5. On the hand-held tester or OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.

   CHECK: 

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

   OK: 

   Temperature value: -40°C (-40°F) 

   Fig 4: Checking For Short In Harness Or ECM And Locating E6 Connector Of ECM

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK : Repair or replace harness and connector. 
   2. NG : Replace ECM (see  COMPONENTS  ).