I need to replace the coolant sensor on my 04 trailblazer. Exactly where is it located?

Hi Janice , Before I say where the coolant temp. sensor is I'd just like to make you aware of a couple of thing's before you replace this sensor needlessly .It's one thing if you have a DTC diagnostic trouble code for the sensor but another if your temp. gauge isn't work ! You see the coolant temp. sensor is an input to the engine computer , not directly to the temp. gauge.
The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the engine control module (ECM). The IPC receives a serial data message from the ECM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 100°F (40°C) or below if: ?€¢
The ECM detects a malfunction in the engine coolant temperature sensor circuit.

?€¢
The IPC detects a loss of serial data communications with the ECM.

code p0128 refers to coolant thermostat--coolant below thermostat regulating temperature==causes mechanical fault. ( thermostat stuck open --replace it) If you are experiencing cold weather then there is a problem with the ecm settings as the ecm should be compensating for the cold ambient temperature and setting the fuel mixture to richer than normal ( same as using a choke). Check the fault codes again and check for a coolant sensor fault.

It can be faulty coolant temperature sensor.Its not sensing exact coolant heat temperature so its overheating then required level.

-----------

Get the coolant pressure tested, its definitely leaking coolant. You will need to get the coolant running line.

Pressure test will help you to know from where exactly coolant/refrigerant is getting leaked.

===========

For complete step by step troubleshooting i suggest you to go through the help links mentioned below :----

Click the link below :-----

Coolant enters in transmission on Toyota Land cruiser?

http://schematicsdiagram.blogspot.com/2012/01/coolant-enters-in-transmission-on.html

--------------

1991 Toyota Camry: Order Coolant Bypass Tube?

http://whatisbyme.blogspot.in/2012/05/1991-toyota-camry-order-coolant-bypass.html

-------------

2002 Toyota Camry: Puff of Blue or White Smoke while Starting?

http://whatisbyme.blogspot.in/2012/05/2002-toyota-camry-puff-of-blue-or-white.html

----------------

1994 Toyota Camry: Coolant Leak?

http://technoanswers.blogspot.in/2012/04/1994-toyota-camry-coolant-leak.html

----------

2006 Cadillac DTS: COOLANT LEAK AT DRIVER SIDE NEAR FIREWALL?

http://schematicsdiagram.blogspot.in/2012/04/2006-cadillac-dts-coolant-leak-at.html

----------

MAF, IAT, MAP and Coolant Level Sensor problem all together on Mazda MPV?

http://schematicsdiagram.blogspot.com/2011/12/maf-iat-map-and-coolant-level-sensor.html

---------------

GMC Engine Coolant Temperature (ECT) Sensor Replacing?

http://schematicsdiagram.blogspot.com/2011/12/gmc-engine-coolant-temperature-ect.html

------------

Loosing Coolant?

http://whoisbyme.blogspot.in/2012/06/loosing-coolant.html

---------------

Coolant temperature sensor dies again and again?

http://schematicsdiagram.blogspot.com/2012/01/coolant-temperature-sensor-dies-again.html

------------

2000 Daewoo Lanos: Where to Add Coolant?

http://repairhelpcenter.blogspot.in/2012/06/2000-daewoo-lanos-where-to-add-coolant.html

Blue Water Warning Light on Dash?

http://whatisbyme.blogspot.in/2012/07/blue-water-warning-light-on-dash.html

---------------

Replacing Oldsmobile Engine coolant sensor?

--------------

How to test Engine coolant temperature sensor?

------------------

Replace Coolant Sensor Module on Oldsmobile?

-----------

These details will help.

Thanks.

Get coolant temp sensor checked.

Get the coolant pressure tested, its definitely leaking coolant. You will need to get the coolant running line.

Pressure test will help you to know from where exactly coolant/refrigerant is getting leaked.

===========

For complete step by step troubleshooting i suggest you to go through the help links mentioned below :----

Click the link below :-----

Coolant enters in transmission on Toyota Land cruiser?

http://schematicsdiagram.blogspot.com/2012/01/coolant-enters-in-transmission-on.html

--------------

1991 Toyota Camry: Order Coolant Bypass Tube?

http://whatisbyme.blogspot.in/2012/05/1991-toyota-camry-order-coolant-bypass.html

-------------

2002 Toyota Camry: Puff of Blue or White Smoke while Starting?

http://whatisbyme.blogspot.in/2012/05/2002-toyota-camry-puff-of-blue-or-white.html

----------------

1994 Toyota Camry: Coolant Leak?

http://technoanswers.blogspot.in/2012/04/1994-toyota-camry-coolant-leak.html

----------

2006 Cadillac DTS: COOLANT LEAK AT DRIVER SIDE NEAR FIREWALL?

http://schematicsdiagram.blogspot.in/2012/04/2006-cadillac-dts-coolant-leak-at.html

----------

MAF, IAT, MAP and Coolant Level Sensor problem all together on Mazda MPV?

http://schematicsdiagram.blogspot.com/2011/12/maf-iat-map-and-coolant-level-sensor.html

---------------

GMC Engine Coolant Temperature (ECT) Sensor Replacing?

http://schematicsdiagram.blogspot.com/2011/12/gmc-engine-coolant-temperature-ect.html

------------

Loosing Coolant?

http://whoisbyme.blogspot.in/2012/06/loosing-coolant.html

---------------

Coolant temperature sensor dies again and again?

http://schematicsdiagram.blogspot.com/2012/01/coolant-temperature-sensor-dies-again.html

------------

2000 Daewoo Lanos: Where to Add Coolant?

http://repairhelpcenter.blogspot.in/2012/06/2000-daewoo-lanos-where-to-add-coolant.html

Blue Water Warning Light on Dash?

http://whatisbyme.blogspot.in/2012/07/blue-water-warning-light-on-dash.html

---------------

Replacing Oldsmobile Engine coolant sensor?

--------------

How to test Engine coolant temperature sensor?

------------------

Replace Coolant Sensor Module on Oldsmobile?

-----------

These details will help.

Thanks.

Get the coolant pressure tested,its definitely leaking coolant.You will need to get the coolant running line.
Pressure test will help you to know from where exactly coolant/refrigerant is getting leaked.===========For complete step by step troubleshooting i suggest you to go through the help links mentioned below :----Click the link below :-----

Coolant enters in transmission on Toyota Land cruiser?
http://schematicsdiagram.blogspot.com/2012/01/coolant-enters-in-transmission-on.html
--------------

1991 Toyota Camry: Order Coolant Bypass Tube?

http://whatisbyme.blogspot.in/2012/05/1991-toyota-camry-order-coolant-bypass.html

-------------

2002 Toyota Camry: Puff of Blue or White Smoke while Starting?

http://whatisbyme.blogspot.in/2012/05/2002-toyota-camry-puff-of-blue-or-white.html
----------------

1994 Toyota Camry: Coolant Leak?

http://technoanswers.blogspot.in/2012/04/1994-toyota-camry-coolant-leak.html
----------

2006 Cadillac DTS: COOLANT LEAK AT DRIVER SIDE NEAR FIREWALL?

http://schematicsdiagram.blogspot.in/2012/04/2006-cadillac-dts-coolant-leak-at.html
----------

MAF, IAT, MAP and Coolant Level Sensor problem all together on Mazda MPV?

http://schematicsdiagram.blogspot.com/2011/12/maf-iat-map-and-coolant-level-sensor.html

---------------

GMC Engine Coolant Temperature (ECT) Sensor Replacing?

http://schematicsdiagram.blogspot.com/2011/12/gmc-engine-coolant-temperature-ect.html

------------

Loosing Coolant?

http://whoisbyme.blogspot.in/2012/06/loosing-coolant.html

---------------

Coolant temperature sensor dies again and again?

http://schematicsdiagram.blogspot.com/2012/01/coolant-temperature-sensor-dies-again.html

------------

2000 Daewoo Lanos: Where to Add Coolant?

http://repairhelpcenter.blogspot.in/2012/06/2000-daewoo-lanos-where-to-add-coolant.html

Blue Water Warning Light on Dash?

http://whatisbyme.blogspot.in/2012/07/blue-water-warning-light-on-dash.html
---------------

• Replacing Oldsmobile Engine coolant sensor?

--------------
How to test Engine coolant temperature sensor?
------------------

• Replace Coolant Sensor Module on Oldsmobile?

-----------

These details will help.

Thanks.

Dodge Dakota 3.7L v6:

Fig. ECT sensor location-3.7L, 4.7L engines.

Back to Top Inspect/Test/Replace 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.

Hello;
Can't show you exactly, but is easy to take the grill out and change lamps while it is out! Grill has clips, you just have to un-clip it, pull two tabs on each side on the top and the whole thing comes out! (20 Minutes)

57ChevyGuy

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c152800a1187

Renew the coolant every 24,000 miles or 2 years which ever comes first.
If your battery is in good condition, there is no need to change it.

Driver side engine block behind the alternator.You need to remove the alternator to get to the sensor.