DTC P0115: Engine Coolant Temperature Circuit Malfunction; DTC P0117: Engine Coolant Temperature Circuit Low Input; DTC P0118: Engine Coolant Temperature Circuit High Input: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine / Data List / 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

   Temperature Displayed	Proceed to
   -40°C (-40°F)	A
   140°C (284°F) or more	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) or more.

C → CHECK FOR INTERMITTENT PROBLEMS 

B → See step   4 

A: Go to next step 

1. Confirm good connection of the sensor.
   Fig 1: Identifying ECT Sensor Circuit Diagram

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the B13 engine coolant temperature (ECT) sensor connector.
3. Connect terminals 1 and 2 of the ECT sensor connector on the wire harness side.
4. Connect the Techstream to the DLC3.
5. Turn the engine switch on (IG).
6. Turn the Techstream on.
7. Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.
8. Read the value displayed on the Techstream.

   Standard

   140°C (284°F)

9. Reconnect the ECT sensor connector.

OK → See step   6 

NG: Go to next step 

1. Disconnect the B13 ECT sensor connector.
2. Disconnect the B12 ECM connector.
3. Measure the resistance between the terminals.

   Standard resistance

   Tester Connection	Specified Condition
   THW (B12-79) - B13-2	Below 1 Ω
   ETHW (B12-78) - B13-1	Below 1 Ω

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

OK → See step   7 

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the B13 ECT sensor connector.
   Fig 2: Identifying Terminals Of B13 ECT Sensor Connectors

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

   Standard

   -40°C (-40°F)

7. Reconnect the ECT sensor connector.

OK → See step   6 

NG: Go to next step 

1. Disconnect the B13 ECT sensor connector.
2. Disconnect the B12 ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Specified Condition
   THW (B12-79) or B13-2 - Body ground	10 kΩ or higher

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

OK → See step   7 

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR