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

READ VALUE USING TECHSTREAM (ENGINE COOLANT TEMPERATURE)

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Read the value displayed on the Techstream.

Standard value

Between 75°C and 100°C (167°F and 212°F) with warm engine.

Result

Result	Proceed to
-40°C (-40°F)	A
Higher than 135°C (275°F)	B
Between 75°C and 100°C (167°F and 212°F)	C

HINT:

If there is an open circuit, the Techstream indicates -40°C (-40°F).

If there is a short circuit, the Techstream indicates higher than 135°C (275°F).

B → See step 7

C → See step 4

A: Go to next step

READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)
1. Disconnect the engine coolant temperature sensor connector.
  
  Fig 1: Engine Coolant Temperature Sensor Circuit Diagram
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect terminals 1 and 2 of the engine coolant temperature sensor connector on the wire harness side.
3. Connect the Techstream to the DLC3.
4. Turn the ignition switch to ON.
5. Turn the Techstream on.
6. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
7. Read the value displayed on the Techstream.
  Standard value
  
  Higher than 135°C (275°F)
8. Reconnect the engine coolant temperature sensor connector.
NG → See step 3

OK → See step 5

CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)

Disconnect the engine coolant temperature sensor connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
B3-2 - B29-64 (THW)	Always	Below 1 Ω
B3-1 - B29-65 (ETHW)	Always	Below 1 Ω

Reconnect the engine coolant temperature sensor connector.
Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)

OK → See step 6

CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS
REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to REMOVAL
REPLACE ECM. Refer to REMOVAL
READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
1. Disconnect the engine coolant temperature sensor connector.
  
  Fig 2: Engine Coolant Temperature Sensor Circuit Diagram
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
6. Read the value displayed on the Techstream.
  Standard value
  
  -40°C (-40°F)
7. Reconnect the engine coolant temperature sensor connector.
NG → See step 8

OK → See step 9

CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)

Disconnect the engine coolant temperature sensor connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
B3-2 or B29-64 (THW) - Body ground	Always	10 kΩ or higher

Reconnect the engine coolant temperature sensor connector.
Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)

OK → See step 10

REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to REMOVAL
REPLACE ECM. Refer to REMOVAL