Toyota Tundra. Manual — part 1169

Fig. 69: Identifying D28 Engine Coolant Temperature Sensor Connector Terminals

OK : CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT
TEMPERATURE SENSOR (See REMOVAL )

4. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR -

ECM)

a. Disconnect the D28 ECT sensor connector.

b. Disconnect the D74 ECM connector.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

Tester Connection

Condition Specified Condition

D28-2 - D74-76 (THW)

Always

Below 1 ohms

D28-1 - D74-97 (ETHW) Always

Below 1 ohms

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

Fig. 70: Identifying D28 ECT Sensor & D74 ECM Connector Terminals

OK : GOOD CONNECTION TO ECM. IF OK, REPLACE ECM (See REMOVAL )

5. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)

a. Disconnect the D28 ECT sensor connector.

b. Connect the Techstream to the DLC3.

c. Turn the ignition switch ON (IG).

d. Turn the Techstream ON.

e. Enter the following menus: Powertrain/Engine and ECT/Data List/All Data/Coolant Temp.

f. Read the value displayed on the Techstream.

Standard value:

-40°C (-40°F)

NG : Go to step 6

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

Fig. 71: Disconnecting D28 ECT Sensor Connector

OK : REPLACE ENGINE COOLANT TEMPERATURE SENSOR (See REMOVAL )

6. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR -

ECM)

a. Disconnect the D28 ECT sensor connector.

b. Disconnect the D74 ECM connector.

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

Tester Connection

Condition Specified Condition

D28-2 or D74-76 (THW) - Body ground Always

10 kohms or higher

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

Fig. 72: Identifying D28 ECT Sensor & D74 ECM Connector Terminals

OK : REPLACE ECM (See REMOVAL )

DTC P0116 ENGINE COOLANT TEMPERATURE CIRCUIT RANGE/PERFORMANCE PROBLEM

DESCRIPTION

Refer to DTC P0115 .

DTC TROUBLE DETECTION CONDITION CHART

MONITOR DESCRIPTION

Engine coolant temperature (ECT) sensor cold start monitor

When a cold engine start is performed and then the engine is warmed up, if the ECT sensor value does not
change, it is determined that a malfunction has occurred. If this is detected in 2 consecutive driving cycles, the

DTC

No.

DTC Detection Condition

Trouble Area

P0116

When either of following conditions met (2 trip detection logic)



When cold engine started and engine warmed up, Engine Coolant
Temperature (ECT) sensor value does not change.



After warmed up engine stopped and then next cold engine start
performed, ECT sensor value does not change.



Thermostat



ECT
sensor

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra