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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

CHECK DTC OUTPUT

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Select the following menu items: Powertrain / Engine / Trouble Code.

Read the DTCs.

Result

Display (DTC Output)	Proceed to
P0115	A
P0117	B
P0118	C

C → See step 4

B → See step 7

A: Go to next step

READ VALUE USING ENGINE COOLANT TEMPERATURE SENSOR (COOLANT TEMP)

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Enter the following menus: Powertrain / Engine / Data List / Coolant Temp.

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)	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).

C → CHECK FOR INTERMITTENT PROBLEMS

B → See step 6

A: Go to next step

CHECK ENGINE COOLANT TEMPERATURE SENSOR (CHECK FOR OPEN IN SENSOR)
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 9

NG: Go to next step

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

Disconnect the B13 ECT sensor connector.

Fig 2: Identifying B12 ECM Connector Terminal & B13 ECT Sensor Connector Terminal
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the B12 ECM connector.

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

Reconnect the ECM connector.
Reconnect the ECT connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → See step 5

REPLACE ECM. Refer to REMOVAL
CHECK ENGINE COOLANT TEMPERATURE SENSOR (CHECK FOR SHORT IN SENSOR)
1. Disconnect the B13 ECT sensor connector.
  
  Fig 3: 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 10

NG: Go to next step

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

Disconnect the B13 ECT sensor connector.

Fig 4: Identifying B12 ECM Connector Terminal & B13 ECT Sensor Connector Terminal
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the B12 ECM connector.

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

Reconnect the ECT sensor connector.
Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → See step 8

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