Inspection Procedure

HINT:

• If DTCs P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may be open.
• Read freeze frame data using OBD II scan tool or hand-held tester. Because freeze frame records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining 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 of the malfunction.

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.

   CHECK: 

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

   OK: 

   Same as actual intake air temperature. 

   HINT:

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

   PREPARATION: 

   1. Disconnect the mass air flow meter connector.
   2. Connect the sensor wire harness terminals together.
   3. Turn the ignition switch ON.

   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 1: Connecting Sensor Wire Harness Terminals Together

   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. Remove the glove compartment (See ENGINE CONTROL MODULE (ECM) ).
   2. Connect between terminals THA and E2 of the ECM connector.

      HINT:

      The mass air flow meter connector is disconnected. Before checking, do a visual and contact pressure check for the ECM connector (See PROCEDURE ).

   3. Turn the ignition switch ON.

   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 Between Terminals THA & E2 Of The ECM Connector

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

   PREPARATION: 

   1. Disconnect the mass air flow meter connector.
   2. Turn the ignition switch ON.

   CHECK: 

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

   OK: 

   Temperature value: -40°C (-40°F) 

   Fig 3: Disconnecting 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. Remove the glove compartment (See ENGINE CONTROL MODULE (ECM) ).
   2. Disconnect the E5 connector from the ECM.

      HINT:

      Mass air flow meter connector is disconnected.

   3. Turn the ignition switch ON.

   CHECK: 

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

   OK: 

   Temperature value: -40°C (-40°F) 

   Fig 4: Checking For Short In Harness Between Mass Air Flow Meter & ECM

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