Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2004 Toyota Tacoma PreRunner V6-3.4L (5VZ-FE)FACTORY OEM SERVICE PROCEDURE
Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection
INSPECTION
1. DRAIN ENGINE COOLANT
2. DISCONNECT UPPER RADIATOR HOSE FROM WATER OUTLET
3. REMOVE NO.2 TIMING BELT COVER
4. REMOVE FUEL PIPE
Remove the 2 union bolt, 4 gaskets and fuel pipe.
5. REMOVE ECT SENSOR
a. Disconnect the ECT sensor connector.
b. Using a 19mm deep socket wrench, remove the ECT sensor and gasket.
6. INSPECT ECT SENSOR
Using an ohmmeter, measure the resistance between the terminals.
Resistance: Refer to the graph
If the resistance is not as specified, replace the ECT sensor.
7. REINSTALL ECT SENSOR
a. Install a new gasket to the ECT sensor.
b. Using a 19 mm deep socket, install the ECT sensor.
Torque: 20 N.m (200 kgf.cm, 14 ft.lbf)
c. Connect the ECT sensor connector.
8. REINSTALL FUEL PIPE
Install the fuel pipe with 4 new gaskets and the 2 union bolts.
Torque: 34.3 N.m (350 kgf.cm, 25 ft.lbf)
9. REINSTALL NO.2 TIMING BELT COVER
10. RECONNECT UPPER RADIATOR HOSE TO WATER OUTLET
11. REFILL WITH ENGINE COOLANT
1. DRAIN ENGINE COOLANT
2. DISCONNECT UPPER RADIATOR HOSE FROM WATER OUTLET
3. REMOVE NO.2 TIMING BELT COVER
4. REMOVE FUEL PIPE
Remove the 2 union bolt, 4 gaskets and fuel pipe.
5. REMOVE ECT SENSOR
a. Disconnect the ECT sensor connector.
b. Using a 19mm deep socket wrench, remove the ECT sensor and gasket.
6. INSPECT ECT SENSOR
Using an ohmmeter, measure the resistance between the terminals.
Resistance: Refer to the graph
If the resistance is not as specified, replace the ECT sensor.
7. REINSTALL ECT SENSOR
a. Install a new gasket to the ECT sensor.
b. Using a 19 mm deep socket, install the ECT sensor.
Torque: 20 N.m (200 kgf.cm, 14 ft.lbf)
c. Connect the ECT sensor connector.
8. REINSTALL FUEL PIPE
Install the fuel pipe with 4 new gaskets and the 2 union bolts.
Torque: 34.3 N.m (350 kgf.cm, 25 ft.lbf)
9. REINSTALL NO.2 TIMING BELT COVER
10. RECONNECT UPPER RADIATOR HOSE TO WATER OUTLET
11. REFILL WITH ENGINE COOLANT
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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