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 engine coolant 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 engine coolant 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 engine coolant temperature sensor 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 engine coolant temperature sensor. 
   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 THW and E2 of the ECM connector.

      HINT:

      The engine coolant temperature sensor 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 Terminals THW And E2 Of ECM Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Open in harness between terminal E2 or THW, 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 engine coolant temperature sensor 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: Checking Short Harness And ECM

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Replace engine coolant temperature sensor. 
   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:

      The engine coolant temperature sensor 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: Disconnecting E5 Connector From ECM

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