# Sentra 2004 1.8 - P0128 - ECT sensor



## milford (Jan 10, 2008)

I have sentra 2004 1.8S with 44,000 miles. the "service engine soon" light came on and I went to autozone to check out what is the problem. They checked and told me I have P0128 code. 

They told me three thing to ckeck:

1. Check coolant level ( which is fine)
2. Thermostat defective (It was fine but I still changed it)
3. ECT (engine coolant temperature) sensor defective

Change the Thermostat(which was fine) but still getting light. Last thing is to change the sensor.

So my question is:

Where is ECT sensor located and is easy to change?

Any info will be helpful.

Thanks


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## rps180 (Aug 20, 2005)

It should be on the left side of the engine (your right when you are looking at the engine).
Most likely it has a gray connector, right next to a black connector.
Correct me if I am wrong guys, I am only going by memory here.


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## blownb310 (Jun 10, 2002)

milford said:


> So my question is:
> 
> Where is ECT sensor located and is easy to change?
> 
> Thanks


Yes indeed, it is very easy to change. It's located in the front of the cylinder head, right behind the top alternator bracket [which is not in the way]. Make sure the engine is cold. Then simply depress the tab in on the gray electrical harness connector and pull it off of the old sensor. Then all you need is a 19mm deep socket to remove and install the new one. Do it quickly and you won't lose much coolant. Make sure you include the brass sealing washer that comes with the new one, otherwise it will leak. Then top up the overflow bottle if it is low.

Mike


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## jdg (Aug 27, 2009)

Ya know that was 3 years ago, right?


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## blownb310 (Jun 10, 2002)

jdgrotte said:


> Ya know that was 3 years ago, right?


Yup,

It was put there to help others with the same problem save time and get all of the correct details in one place. When I googled the search terms "2005 Sentra P0128" this thread came up on top, but it gave no usable answer to the original question asked. Now it is a useful thread. 

Mike


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## blownb310 (Jun 10, 2002)

Maybe milford might actually post a thank you note to us now. Don't you love those people who only make one post asking for help and then disappear and not even make a follow up post describing if/how the problem was solved?


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## blownb310 (Jun 10, 2002)

Might as well go the extra mile for my Sentra friends. Here's a pic of the location of the ETC sensor:










Close up:










The Nissan part number is 22630-ED000. It's like $29.


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## jdg (Aug 27, 2009)

blownb310 said:


> Yup,


OK, just checking.
Your reply is right on of course...


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## kevinweitzeil (Jul 27, 2013)

*Thank you =)*

I don't know about millford, but I will certainly thank you all for continuing this thread 3 years at a time lol.

I have an '89 Sentra and it sounds like this is exactly the problem I'm having with it. It keeps reading hot, but on popping the hood, doesn't *feel* like it's overly hot. We just moved to Phoenix from Seattle and on the trip down we experienced ACTUAL overheating problems - on opening the hood you could hear and feel the water boiling and there was just an overwhelming blast of heat coming from the engine compartment.

Now, it's reading at almost the same temp as when that happened, but looks/feels like no more than a normal running motor. Just replaced the head gasket and water pump. No leaks anywhere of either oil or water.

And thanks for the pics too, blown, super helpful.


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## Dadof6 (Feb 22, 2014)

*Thanks*

Big thanks to Blownb!! Your picture was right on target. Thanks for the help!!


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## ShotsAlot (Jun 20, 2015)

You guys realize it's been two years later after the initial three years, right? I'm thankful for this forum because I have a 2000 Nissan Sentra DLX or something like that with a 1.8L engine that's been beating me up.

My car is overheating- I replaced the radiator after it cracked on the plastic top end. 2 months go by.I then replaced the thermostat because the car was overheating.A month later the car overheated again at an idle with the a/c turned on. I don't see any leaks around the water pump, the coolant fan turns on independently from the a/c fan. I'm thinking the ECT is intermittent or the heater core is plugged up? Thanks guys (Mike & Blown) for posting this topic, it'll help me and help my wallet. Yes I have a wallet, my bills aren't crinkled up.


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## engineer1025 (Feb 19, 2016)

Thanks to all for keeping this post going - this was exactly what i needed!


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