Where is the coolant temperature sensor located on a 2005 Chevy Trailblazer

Find the coolant temperature sensor on the front of the engine block, just behind the alternator. Pull upward on the locking tab on the coolant temperature sensor’s wiring harness, and pull the wiring harness from the sensor.

Where is the coolant temp sensor located?

The Engine Coolant Temperature Sensor can be located in a few places, depending on the vehicle and its manufacturer. It is most often located close to the thermostat of the cooling system or inside of it. The cooling system is located beneath the air intake pipe and behind the right cylinder.

What problems can a bad coolant temperature sensor cause?

Your Engine is Overheating While a failing engine coolant temperature sensor may give a permanent cold signal, it can also malfunction in a way that sends a hot signal when your engine temperature is safe.

What are the symptoms of a bad temperature coolant sensor?

Check Engine Light. …
Poor Mileage. …
Electrical Cooling Fans not coming on. …
Black Smoke from the Exhaust Pipe. …
Difficult Starting Condition. …
Engine Overheats. …
Poor Idling. …
Poor Engine performance.

What happens if you unplug the coolant temp sensor?

What Happens If You Unplug The Coolant Temp Sensor? Unplugging the engine coolant sensor while the car is running will likely cause the engine to stumble and run rough. The engine light may not come on imminently, but a DTC (Diagnostic Trouble Code) will be logged in the PCM.

Where is the temperature sensor on a Chevy Trailblazer?

On the 02-05 Trailblazer 4.2,the ECT sensor is located on the driver side near the front, behind the alternator directly above the thermostat/housing. Coolant temperature sensor is located on the radiator next to the front of the engine.

How much does it cost to replace a coolant temperature sensor?

The average price for an engine temperature sensor replacement is between $150 and $193. Labor costs are between $82 and $105 while parts are between $66 and $88.

What does engine code P0128 mean?

Code P0128 stands for Engine Coolant Temperature Below Thermostat Regulating Temperature. It means that the ECM/PCM has “noticed” that the engine coolant temperature is consistently running below thermostat regulating temperature. In other words, the engine is running cooler than it should.

Where is the thermostat on a 2005 Trailblazer?

the thermostat is located on the drivers side of the engine, just to the rear of the alternator, if memory serves correctly (I’m not looking this up or looking at that particular engine to pass on general info). The ECT (Engine Coolant Temperature) sensor is located directly above it.

How do you check a temperature sensor?

Submerge your temperature sensor in the hot water and wait a few seconds to let your multimeter take a reading. Write down your reading so you can easily reference it. A hot water reading should give you around .

Article first time published on

Is there a fuse for coolant temperature sensor?

There isn’t one per se. There will be a fused wire with voltage to the instrument cluster (your owners manual should indicate which fuse), but the temperature sensor is providing a variable “resistance to ground,” which the temperature gauge in the dash is reflecting.

Does the coolant temp sensor control the fan?

The resistance of the sensor varies with temperature, this is how the ECU can monitor temperature changes. The ECU uses this reading to calculate the coolant temperature, and from there adjusts the fuel injection, fuel mix, and ignition timing, and controls when the electric cooling fan is switched on and off.

Can you clean a coolant temperature sensor?

In most cases, sensors for your automobile will need to be replaced if they fail, but depending on the type of sensor and its location or function, some can be cleaned and reused. Sensors can come in many types and are used for a variety of systems on modern cars.

Can a temp sensor affect engine starting?

If the sensor is reading too high of temperature when compared to the ambient air temperature sensor when first started then the computer would see it as a problem and turn on the check engine light to use a known good reading. No start will not be caused by the sensor.

How long does it take to replace a coolant temperature sensor?

The actual process of replacing the coolant temperature sensor is extremely simple. However, the difficult work comes in the preparation of the cooling system – both before and after. Tip: This job should only be completed when the engine is cold and has not been running for a minimum of one hour.

What is a ambient air temperature sensor?

Thermometrics Ambient Air Temperature Sensor measures the temperature outside the passenger compartment and is usually mounted inside or near the front bumper. The sensor provides input to automatic HVAC systems to help control the interior temperature of the automobile.

Where is the thermostat located on a 2008 Chevy Trailblazer?

Locate the thermostat housing that sits near the front of the engine at the top. The thermostat housing will be at the end of the upper radiator hose, connected to the motor.

Where is the thermostat located at on a 2005?

The thermostat is on the right side of the engine when facing the engine from the front(drivers side). It is under the air duct. It is a difficult job to replace, you must remove the duct, the air cleaner housing, and the black pipe above the thermostat housing so you can get your hands at the bolts.

How much is a thermostat for a 2004 Trailblazer?

2004 Chevrolet Trailblazer Thermostat – from $29.99+ | AutoZone.com.

Will a bad thermostat throw a code?

the most noticeable issues occur when the thermostat gets stuck in either the open or closed position. a malfunction can result in a trouble code, generated by the engine’s computer, which can turn on your check engine light.

Can low coolant cause P0128?

Low engine coolant can alter the engine running temperature enough to signal trouble code P0128. Your intake air temperature sensor, coolant temperature sensor and coolant fan could also signal this trouble code, so these should be inspected after you look over your thermostat and coolant level.

Can a bad coolant temp sensor cause rough idle?

A faulty coolant sensor that always reads cold may cause the fuel control system to run rich, pollute and waste fuel. A coolant sensor that always reads hot may cause cold driveability problems such as stalling, hesitation and rough idle. … This also affects engine performance and fuel economy.

Why is my temperature gauge stuck on hot?

Common reasons for this to happen: Low Coolant: The first suspected cause of your temperature gauge maxing out is low coolant. … The needle may be stuck in the hot range (this can happen after overheating the engine), or a stepper gear in the gauge may be damaged.

Why is my temp gauge all the way up?

The primary reason your car temperature gauge goes up and down while driving is simply because a component in your cooling system is not functioning correctly. This could be the thermostat valve, radiator hoses, radiator fan, the temperature gauge, or the coolant itself that circulates around cools off the engine.

How do you use a multimeter to check a temperature gauge?

Turn your vehicle on and let it warm up. Disconnect the gauge signal wire from the sender and check the ohms output between the sender and common ground/chassis with a multimeter. Compare the ohms output with the expected ohm output at warm temperature.

What sensor controls the temperature gauge?

To troubleshoot your car’s temperature gauge, you need to know how it works. The temperature gauge reading starts out as a reference voltage that is sent to the coolant temperature sensor. This sensor is nothing more than a thermistor — a variable resistor that changes resistance with temperature changes.