Inspection Procedure

HINT:

• If DTCs related 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 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 OBD II scan tool or hand-held tester, and read value of intake air temperature. 

   PREPARATION: 

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

   CHECK: 

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

   OK: 

   1. Same as actual intake air temperature. 

   RESULT: 

   Temperature Display Table
   
   

   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 OBD II scan tool or the hand-held tester indicates -40°C (-40°F).
   • If there is a short circuit, the OBD II scan tool or the hand-held tester 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 1 and 2 of the mass air flow meter wire harness side connector.
   3. Turn the ignition switch ON.
   4. When using hand-held tester, enter the following menus: DIAGNOSTICS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.

   CHECK: 

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

   OK: 

   1. Temperature value: 140°C (284°F) or more 
   Fig 1: Connecting Terminals 1 and 2 of Mass Air Flow Meter harness Side Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Confirm good connection at sensor. If OK, replace mass air flow meter. 
   2. NG: Go to Next Step 
3. Check for open in harness or ECM. 

   PREPARATION: 

   1. Connect terminals THA and E2 of the E5 ECM connector.

      HINT:

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

   2. Turn the ignition switch ON.
   3. When using hand-held tester, enter the following menus: DIAGNOSTICS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.

   CHECK: 

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

   OK: 

   1. Temperature value: 140°C (284°F) or more 
   Fig 2: Connecting Terminals THA and E2 of E5 ECM connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Repair or replace harness or connector. 
   2. NG: Confirm good connection at ECM. If OK, check and replace ECM (See  INSPECTION  ). 
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. When using hand-held tester, enter the following menus: DIAGNOSTICS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.

   CHECK: 

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

   OK: 

   1. Temperature value: -40°C (-40°F) 
   Fig 3: Disconnecting M1 Mass Air Flow Meter Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Replace mass air flow meter. 
   2. NG: Go to Next Step 
5. Check for short in harness or ECM. 

   PREPARATION: 

   1. Disconnect the E5 ECM connector.
   2. Turn the ignition switch ON.
   3. When using hand-held tester, enter the following menus: DIAGNOSTICS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.

   CHECK: 

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

   OK: 

   1. Temperature value: -40°C (-40°F) 
   Fig 4: Disconnecting E5 ECM Connector

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