How to replace Coolant Temperature Sensor?

Coolant Temperature Sensor Operation:

This sensor monitors the temperature of the engine and sends that information to the engine control computer to regulate the amount of fuel needed. More fuel is needed if the engine is cold; less if it's hot. If the temperature is extreme, the signal will be sent to the temperature gauge as a visual indicator of overheating and imminent danger.

See below how this sensor looks:---


Inspect the sensor's wires and connections. ECT (engine coolant temperature) sensor problems are often caused by faulty wiring or loose or corroded connections rather than the failure of the sensor itself.

If the wires or connections are bad, replace them. If you think the sensor is defective, it should be tested.

WARNING

Never apply an open flame to an ECT (engine coolant temperature) or IAT (intake air temperature) sensor for test purposes. This action will damage the sensor.

A defective ECT sensor may cause some of the following problems:

• Hard engine starting
• Rich or lean air/fuel ratio
• Improper operation of emissions devices
• Reduced fuel economy
• Improper converter clutch lockup
• Hesitation on acceleration
• Engine stalling

The ect sensor may be removed and placed in a container of water with an ohmmeter connected across the sensor terminals. a thermometer is also placed in the water. when the water is heated, the sensor should have the specified resistance at any temperature. if the sensor does not have the specified resistance, replace the sensor.

The wiring to the sensor can also be checked with an ohmmeter. With the wiring connectors disconnected from the ECT sensor and the computer, connect an ohmmeter from each sensor terminal to the computer terminal to which the wire is connected. Both sensor wires should indicate less resistance than specified by the vehicle manufacturer. If the wires have higher resistance than specified, the wires or wiring connectors must be repaired.

WARNING

Before disconnecting any computer system component, be sure the ignition switch is turned off. Disconnecting components may cause high induced voltages and computer damage.

With the sensor installed in the engine, the sensor terminals may be backprobed to connect a digital voltmeterto the sensor's terminals. the sensor should provide the specified voltage drop at any coolant temperature.

Voltage drop specifications for an ECT sensor.

Some computers have internal resistors connected in series with the ECT sensor. The computer switches these resistors at approximately 120° F (49° C). This resistance change inside the computer causes a significant change in voltage drop across the sensor, as indicated in the specifications. This is a normal condition on any computer with this feature. This change in voltage drop is always evident in the vehicle manufacturer's specifications.

Because ECT (engine coolant temperature) sensor procedures vary depending upon their location, first locate the part. You may need to partially drain the engine coolant to prevent coolant spillage.

• Disconnect the negative battery cable.
• Unplug the ECT.
• Then, unscrew it.
• Reverse the removal procedures to install the new part.
• Connect the negative battery cable to the battery.

This details will help.

Thanks

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Replace Coolant Sensor Module on Oldsmobile?

The details are a follows :----

The low coolant module activates a light in the instrument cluster when coolant in the radiator goes below a certain level (closed with low coolant level). It has two terminals. Terminal B is the connection from the sensor to the instrument panel. Terminal C is the sensor's ground connection. The sensor is located in the radiator's right side tank.

TESTING

"LOW COOLANT" Indicator ON, Coolant Level OK

1. Disconnect the engine coolant level indicator module at the radiator.
2. Place the ignition switch in the ON position. Check if the "Low Coolant" indicator is ON.
   1. If the indicator is no longer ON, replace the coolant level indicator module.
   2. If the indicator is still ON, check the circuit for a short to ground, between the instrument cluster connection and the module connector terminal B (usually a yellow/black wire, to instrument cluster).
   3. If the circuit is okay, the instrument cluster may need to be serviced.

"LOW COOLANT" Indicator OFF, Coolant Level LOW

1. Disconnect the engine coolant level indicator module at the radiator.
2. Place the ignition switch in the ON position.
3. Connect a 3 Amp fused jumper between the engine coolant level indicator module terminal B and ground.
4. Is the "Low Coolant" indicator ON-
   1. If the indicator is still ON, connect the fused jumper between terminal B and terminal C (the ground wire, usually black with a white tracer). If the indicator stays ON, check the module terminal C for a poor connection. If okay, replace the module. If the indicator is OFF, check the coolant module terminal C for a poor connection. If okay, look for an open in the circuit between the coolant module and its ground connection, at the flywheel end of the engine.
   2. If, after jumping terminal B and C together, the indicator is now OFF, look for a bad connection at the instrument cluster, an open in the circuit between the coolant level module and instrument cluster connection and/or also a possible bad bulb or bulb connection.

REMOVAL & INSTALLATION

1. Partially drain the radiator to a level below the sensor. See .
2. Unplug the electrical connector from the low coolant sensor.
3. The sensor is retained by a snap clip. To unlock the sensor, lift one leg of the snap clip from its locked position and pull outward with a slight twisting motion.

Fig. Typical engine coolant level indicator module arrangement

To install:

4. Inspect the O-ring on the sensor. If serviceable, lubricate with coolant.
5. Place the snap clip in place and install the sensor to the radiator.
6. Plug the electrical connector to the sensor.
7. Refill the cooling system with the proper mix of DEX-COOL® and water and properly bleed the cooling system. Please see .
8. Check for leaks.

This will help.

Thanks.