DTC P0115: Engine Coolant Temperature Circuit Malfunction (FROM 12/2010); DTC P0117: Engine Coolant Temperature Circuit Low Input (FROM 12/2010); DTC P0118: Engine Coolant Temperature Circuit High Input (FROM 12/2010): Procedure

1. Connect Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
5. Read the value displayed on the Techstream.

   Standard

   Between 80°C and 97°C (176°F and 207°F) with warm engine.

   Result

   Result	Proceed to
   -40°C (-40°F)	A
   140°C (284°F)	B
   Between 80°C and 97°C (176°F and 207°F)	C

   HINT: 

   • If there is an open circuit, Techstream indicates -40°C (-40°F).
   • If there is a short circuit, Techstream indicates 140°C (284°F).

B → See step   5 

C → See step   8 

A: Go to next step 

1. Confirm good connection of the sensor.
   Fig 1: Identifying ECT Sensor Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the engine coolant temperature (ECT) sensor connector.
3. Connect terminals 1 and 2 of the ECT sensor connector on the wire harness side.
4. Connect Techstream to the DLC3.
5. Turn the ignition switch to ON.
6. Turn the Techstream on.
7. Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
8. Read the value displayed on the Techstream.

   Standard

   140°C (284°F).

9. Reconnect the ECT sensor connector.

OK → REPLACE ENGINE COOLANT TEMPERATURE SENSOR 

NG: Go to next step 

1. Disconnect the ECT sensor connector.
2. Disconnect the ECM connector.
3. Measure the resistance between the terminals.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   B50-79 (THW) - B9-2	Always	Below 1 Ω
   B50-78 (ETHW) - B9-1	Always	Below 1 Ω

4. Reconnect the ECM connector.
5. Reconnect the ECT sensor connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4 

1. Disconnect the ECT sensor connector.
   Fig 2: View Of ECT Sensor Circuit

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Enter the following menus: Powertrain / Engine / Data List / All Data / Coolant Temp.
6. Read the value displayed on the Techstream.

   Standard

   -40°C (-40°F)

7. Reconnect the ECT sensor connector.

OK → REPLACE ENGINE COOLANT TEMPERATURE SENSOR 

NG: Go to next step 

1. Disconnect the ECT sensor connector.
2. Disconnect the ECM connector.
3. Measure the resistance between the terminals.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   B50-79 (THW) or B9-2 - Body ground	Always	10 kΩ or higher

4. Reconnect the ECT sensor connector.
5. Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   7