coolant temperature sensor location

Yz2K130

Member
Joined
May 27, 2004
Location
Baton Rouge, LA
TDI
01 Jetta, black
I tried searching but could not find where the sensor is located on an 01 Jetta auto? If anyone has pics, that would be even better.
 

Curious Chris

Top Post Dawg
Joined
Jun 11, 2001
Location
Pineview GA
TDI
Jetta Wagon 2003 RIP Rockford IL
Wow second time in one day that someone asks the same question, go figure. Here is the picture:



Item 6 is the coolant tempersture sensor that if disconnected gives you 20 seconds of glow plug on as the ECM thinks it is really cold.

Oh words next to the picture would be:

6 - Engine Coolant Temperature (ECT) Sensor -G62-
Color: blue
For engine control module
with Engine Coolant Temperature (ECT)Sensor -G2-
Before removing release pressure if necessary

Oh after my initial post my brain engage and remembered my Factory Service CD has color pictures in the wiring chart section so here it is:



Of course in your car those pipes have hose attached to them so it won't be that easy to see!!
 

iceman321

Active member
Joined
Aug 20, 2003
Location
nowhere
TDI
123
i guess after reading the forums here and vwvortex - maybe i shoulda asked for a DIY

anyway to no avail -- i did everything *well what i thought was correctly*

found the temp coolant sensor -
moved the hose to the MAF
pulled the pin out *which was a pain in the arse*
then I was like yeah get to remove my temp coolant sensor*
*****remind you - my car had been sitting for 4 hours*****
anywho -- WHOOOSH -- yeah you guessed it coolant all over - and well - it was quickly stopped when i put the temp sensor back in --

SOOO im low on coolant -- getting some today *from the dealer* -- BY chance do i have to get this done at the dealer or did i do this this totally and utterly wrong ??? do i need to release the pressure from the coolant tank -- or clamp off the hoses or what --

also can someone explain the wire(s) that are coming off the TCS --

and help would be GREATLY appreciated -- i dont like driving with the CEL on - and more improtantly with the temp guage thingy goin on and off - its one hell of an annoying sound

SOOOO -- please respond to those who have done -- and done successfully - i was expecting no leakage and well --

anwyho
 

VelvetFoot

Top Post Dawg
Joined
May 17, 2001
Location
Sand Lake, NY
TDI
NB, 2000, Yellow
Well, at least you didn't do it in the dealer's lot like I did. To be fair to me, I only wanted to put in a new clip because the old one was partly broken. I didn't take into account the pressure thing. They were very cool (as opposed to my coolant) and gave me about 3/4 gal of pre-mix. And my hand hardly blistered at all after keeping ice on it for a while.

If I did it again I think I would:
1-Make sure it was stone cold (overnight at least).
2-Take cap off expansion tank just to be sure to release any pressure and put it back on again.
3-Take electrical lead off old sender and put it on new one before installing sender. If you drop it you won't lose it down there. You are trying to do this quickly.
4-I would recommend getting an extra clip. They are cheap and they break. I think the o-ring is standard, but make sure the new one has one and that you take the old one out.
5-Make sure you have coolant AND distilled water on hand. You want to add it in a 50/50 (or whatever) mix.
6-Make the switch as quick as possible to lose as little coolant as possible.
7-I'd say rinse the engine down some with a hose because the coolant is a little smelly.

Good luck on your adventure!

PS: If I recall, you just have to squeeze hard on that connector. There is a raised piece that you squeeze, I think.
 

iceman321

Active member
Joined
Aug 20, 2003
Location
nowhere
TDI
123
thanks a lot -- i actually talked to a VW mechanic

he basically said the same thing -- but he said they dont wait for it to cool down -- I was like ***???????

but anyway -- yeah the first thing he said was to relieve the pressure !!!! DAMN -- he said you may lose about a teaspoon/tablespoon - but nothing to dramatic to where you will have it GUSH out -

also its a little colder in md right now so the hood is open and i let it sit for about 4 hours and do the replacement with a flash light -- lol anywho -- hopefully this will help people in the future -- my hand has been tinglin all day too its kinda messed up

oh one more thing -- the coolant - i got more i guess i will have to mis it with distilled water somehow? any ways to do that or best way to do it?? pour it in a gallon jug or get soemthing from walmart??? i mean i wouldnt know what to do with the extra

THANKS AGAIN TDIclubers!!!
 

master cylinder

RIP, Gone But Not Forgotten
Joined
May 1, 2002
Location
Brighton, Michigan
TDI
Jetta GLS, 2002, Cool White
If this sensor is the cause of a MIL light, and gets replaced, will the light go out on its own or do you have to reset it with Vag-Com? MIL light came on when coming home tonight. The last time it happened, it was this but was replaced under warranty. Out of warranty now
(still have 300 miles left on replacement part warranty but don't want to risk taking to the dealer to check it out as it may not be the cause then I am stuck paying their exhorbitant fee)
. Don't have Vag-Com yet. How serious do you think it may be (is it OK to drive with MIL on?) Thanks
 

VelvetFoot

Top Post Dawg
Joined
May 17, 2001
Location
Sand Lake, NY
TDI
NB, 2000, Yellow
You could mix up some in a windshield washer bottle. That way you can see how much you put in. I'd keep the coolant. You never know when you might need it, lol.

mastercylinder, I think if the coolant sensor lights the light, it will go out by itself, even if not right away, then after a while. You don't know if this is the problem. They've already replaced it with a newer design that should be more robust. 10k miles isn't so much. Do you have other symptoms than the light? I'm thinking it's something else. There are quite a few tdi'ers in MI. Maybe check the vag-com list, put a request out, etc. Autozone used to read codes for free, but I don't know if they do that any more.
 

iceman321

Active member
Joined
Aug 20, 2003
Location
nowhere
TDI
123
ok really i cant get the plastic off the sensor -- or whatever you call it -- so basically - i have a sensor in and a sensor out -- BUT - no plastic piece to put on the sensor to get the reading!!!!!!! yeah i know im f-ed
 

VelvetFoot

Top Post Dawg
Joined
May 17, 2001
Location
Sand Lake, NY
TDI
NB, 2000, Yellow
What the heck are you talking about, plastic piece? Do you mean the electrical connector? You can't get it off the original sensor?
 

iceman321

Active member
Joined
Aug 20, 2003
Location
nowhere
TDI
123
well i got it off of the original sensor -- boy was that a pain in the arse

anywho -- still getting cel

and i lost more coolant -- so im takin it to the dealerrip-off-ship

peace
 

iceman321

Active member
Joined
Aug 20, 2003
Location
nowhere
TDI
123
well 250 later the coolant temp sensor is ready and well -- im not running hot -- BUT -- now im almost at the 120k mark -- timing belt and apparently *which comes for a 95 dollar fee* 1 of my glow plugs are bad -- yeahhh -- geez anyone wanna buy a tdi ????

;-)
 

master cylinder

RIP, Gone But Not Forgotten
Joined
May 1, 2002
Location
Brighton, Michigan
TDI
Jetta GLS, 2002, Cool White
No symptoms - I do remember the light going off the last time before I took it in for replacement. Not this time - staying on consistently. I can't see or feel anything wrong - runs as perfect as the day it was new. My Brother has the software in his system at work - so he says. I will try to swing by his shop tomorrow and scan for codes - I have the Bentley for DTC's. I suppose if it were anything detrimental it wouldn't be running so good
? ? ?
 

TDI_Michael

Veteran Member
Joined
Feb 25, 2002
Location
Louisiana
TDI
01 Golf GLS
Is this sensor (number 6 on the above diagram) the one that also goes to the temperature gauge inside the car, to the OBD computer or both? I just started having intermittent problems with my gauge indicator, sometimes it reads 190 other times it stays downscale when the vehicle is at normal temp. I checked the wires to this sensor today making sure they were secure and the clip was in place but the problem persists. I also tried to verify whether I had a blue or green temp. sensor but unless I am just not seeing it it appears you have to remove the wiring clip to be sure.
 

VelvetFoot

Top Post Dawg
Joined
May 17, 2001
Location
Sand Lake, NY
TDI
NB, 2000, Yellow
Looks like you need a coolant sensor. I had the same symptoms only on my Beetle. The blue light (no gauge on the Beetle) kept coming on and going off even though the engine was warm. There are two sensors in one. Vag-Com showed an intermittant precipitous drop in indicated temperature, but not on the temperature that the computer uses. Therefore, no MIL.
 

TDIkev

Veteran Member
Joined
Mar 30, 2001
Location
Pickering, Ontario, Canada
TDI
2001 GLS Baltic Green Jetta 5 Spd
Just changed my sensor. Very easy, you just have to disconnect the intake hose so you can get your hand down back to unhook the connector. I lost just a small amount of coolant, probably not enough to have to top up the coolant tank.
I didn't have a problem with the temp gauge or buzzer, just a CEL and when I had it scanned the code was coolant temp sensor.
 

Jettawolfs98

Veteran Member
Joined
Nov 14, 2003
Location
Omaha,NE
TDI
JETTA TDI 2009, JSW 2013 DSG PANO
Hi

This picture is the same for a 2002 model.

Because I have the same problem, but I couldn't find the sensor.

Hopefully you can show me the right picture is this one is not the same.
Thanks
 

iceman321

Active member
Joined
Aug 20, 2003
Location
nowhere
TDI
123
Just changed my sensor. Very easy, you just have to disconnect the intake hose so you can get your hand down back to unhook the connector. I lost just a small amount of coolant, probably not enough to have to top up the coolant tank.
I didn't have a problem with the temp gauge or buzzer, just a CEL and when I had it scanned the code was coolant temp sensor.
i dont know what i did wrong when i did it -- it flowed like a frickin water dam -- it was pouring out the first time -- and even after i released the pressure on the expansion tank - anywho i still wanna know what i did wrong -- granted i got it changed but -- i lost a hell of a lot of fluid!
 

POWERSTROKE

Top Post Dawg
Joined
Jul 17, 2000
Location
Staten Island (The Dump)
TDI
2002 Golf
Was your car cold or hot? I thought if the car was cold, you are not supposed to loosen the expansion cap because it holds a vacuum. IF the car is hot, you would need to unscrew the cap so the fluid doesn't squirt out under pressure. It would be interesting to see your response because I am changing my leaking o-ring on Saturday.
 

VelvetFoot

Top Post Dawg
Joined
May 17, 2001
Location
Sand Lake, NY
TDI
NB, 2000, Yellow
That sounds logical. It would have to be stone cold. I wonder if iceman had the expansion cap open when he did it?
 

Wingnut

Top Post Dawg
Joined
Oct 10, 2002
Location
Toronto & Whitby
TDI
Silver 2003 Jetta Wagon
It is a good idea to keep the cap on while doing the switch. Remove it to release the pressure if there is any, but replace it. Its like pouring a fluid out of a can. If you have no way for the air to replace the lost fliud, the fluid blubs out slower.

[flasback]Ever tried shotgunning a beer. You punch a hole in the bottom of the can with a pen and when you open the top to allow the air in, the beer flows very fast out of the hole in the bottom[/flashback]. I haven't done that since high school.
 

VelvetFoot

Top Post Dawg
Joined
May 17, 2001
Location
Sand Lake, NY
TDI
NB, 2000, Yellow
I like PowerStroke's theory about not opening the cap and letting the engine get stone cold. It might take a while to get stone cold, where there is indeed a vacuum - maybe days??
 

robnitro

Veteran Member
Joined
Jan 19, 2004
Location
NYC area, NY
TDI
2001 Jetta TDI GLS silver
maybe you can release the cap when warm , and then let it cool down with cap on to create a slight vaccuum and then do it at that time?

I have had times when my temp meter was running 1 or 2 clicks lower than the middle. Quite strange, yet the engine ran fine, no limp mode or retardation?

I may oxguard or put silicone on the connector, seeing how the maf connector fix ("cage mod") did wonders for cheap!
 

Jettawolfs98

Veteran Member
Joined
Nov 14, 2003
Location
Omaha,NE
TDI
JETTA TDI 2009, JSW 2013 DSG PANO
Well I still can't find the sensor.
I'm waiiting for my bentley manual.

I'll check on Friday morning after the car is really cold.
 

TDI_Michael

Veteran Member
Joined
Feb 25, 2002
Location
Louisiana
TDI
01 Golf GLS
My coolant sensor on my 01 Golf is going bad and I wanted to pick up one and have it ready to change out but am not sure which one I need. Reading past posts about the different colors of sensors I tried to verify which one I had. The sensor looks black to me, even removed the electrical connector thinking I would see something to give me a clue but no, its not blue or green. Is the color only verified once the sensor is pulled out? According to my VIN and the Bentley manual it is a Brazilian assembled VW.
 

Jettawolfs98

Veteran Member
Joined
Nov 14, 2003
Location
Omaha,NE
TDI
JETTA TDI 2009, JSW 2013 DSG PANO
Well let me tell what happen with the sensor.

First I found it,ok then I got the replace the green one and when I took off the old one and the coolant start coming out, so I kind of freak out and the new sensor the green one slip from my hand to the bottom, Oh my GOD and finally I got it but all the coolant is out and I found that my car has the black one or blue one, but I still can't get the old one out.

So right now I have to fill the coolant again and still don't know if the green one fit, because looks different.

The old one have this number 078919501C

So I'll keep trying to get the old one out.
That thing has a piece of plastic that maybe you have to push it in reder to pull the sensor out.

The question is How to oush that thing in?
I'll keep ypu posted


Anyway not too bad for the first time.
 

VelvetFoot

Top Post Dawg
Joined
May 17, 2001
Location
Sand Lake, NY
TDI
NB, 2000, Yellow
There is a clip that you pull out to get the sensor out. You must have already removed this since the coolant ran out. I think the electrical connector is removed by pushing hard on it with your fingers.
 

dqa

Veteran Member
Joined
Jun 1, 2002
Location
Alabama
TDI
RIP: 1999½ New Golf GL TDI satin silver
The sensor looks black to me, even removed the electrical connector thinking I would see something to give me a clue but no, its not blue or green. Is the color only verified once the sensor is pulled out?
I'll refer you and others here to my thread again, where I ran into some of these problems.
Coolant temp sensor disaster

Short answer to this question is that with a flashlight and from the proper angle, you will only be able to see a sliver of color, if you're lucky.
 
Top