Engine Coolant Temp. Sensor

Vanigh

Well-known member
Joined
Jul 21, 2001
Location
Montreal. Canada
TDI
JETTA TDI 2010 Navy Blue 6 Speed Manual
I had a CEL for the last 2-3 days, i connected the VAG-COM the reading is below


Address 01: Engine Labels: 038-906-012-AGR.lbl
Part No: 038 906 012 CP
Component: 1,9l R4 EDC G000SG 2839
Coding: 00002
Shop #: WSC 00066

1 Fault Found:
16502 - Engine Coolant Temp. Sensor (G62): Signal too High
P0118 - 35-10 - - - Intermittent
Readiness: 1 1 0 0 0

My Question is

1- How Easy is it to replace this sensor?
2- Where is it Located?
3- How much does it cost?
4- Should i take my car to the stealer ship for repair or a mechanic can fix it?

Jetta TDI 2001 Manual
 

Joe_Meehan

Top Post Dawg
Joined
Sep 3, 2005
Location
Ohio USA
TDI
NB TDI, 2002.5, Silver
Do a search. On my 2002 Beetle it was very simple and easy. Took all of about five minutes.
 

CoolAirVw

Vendor
Joined
Nov 9, 2005
Location
Kansas City Missouri
TDI
Jetta
Pull the clip. Have the new o-ring ready on the sensor with some kind of Pick tool to yank out the old o-ring. Then pull out the sensor and o-ring quickly, then reinstall the new one quickly.

Point here is to try to loose as little antifreeze as possible.
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
Just beware that the original o-ring likes to stay inside the sensor mounting flange. Use a small finger or needle nose pliers to remove it, IF it does not come put with the original sensor.

Tony
 

jonmcgarry

Member
Joined
Mar 14, 2010
Location
Ireland
TDI
Passat 2002 Tdi
First thing to remember have some g12 coolant (pink/red) at the ready I changed my sensor the other day it was dropping to minus 9c every now and again then went back up .The sensors location is right across from your catalyst converter on my passat 2002 tdi. The sensor itself comes out towards the left unclip the sensor wiring first the there is a clip facing downwards. Use a flathead to pop this off, be careful if u don't have another. At this stage your ready to take the sensor out the flow of fluid is quite a bit . Once you take out the sensor you will find the o ring seal inside the housing leave it in if you don't have one. I had the sensor + o-ring + clip at the ready I some how managed to loose the o-ring on the new one I used the old one anyway ... but I lost a litre of coolant in the process .. The other thing to remember is don't ever mix anything other than distilled water + G12 coolant it will damage your radiator and reduce your coolant system effectiveness.

It shouldn't take too long to do this about 10 - 20 minutes with good light.
 

Vanigh

Well-known member
Joined
Jul 21, 2001
Location
Montreal. Canada
TDI
JETTA TDI 2010 Navy Blue 6 Speed Manual
Thank you guys for your useful help, much appreciated.
One more question, does the coolant that i have to add has to be VW brand?
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
Yes...Do not mix VW brand with generic coolant. If mixed, they will form a brown goo that is very difficult to clean out of the cooling system.

Besides VW G12(+/++) is pink and if leaks out of the cooling system, will leave a stain and trail to the source of the leak.

Tony
 

adamant628

Veteran Member
Joined
Jul 20, 2009
Location
Columbus, OH
TDI
2003 Jetta Wagon GLS
I've been getting an intermittent P0118 code as well, cleared with scangauge. The code pops up once a week or so. Have you done the repair yet, Vanigh? Let me know how it goes.

PS. What's the difference between the blue and green ones? Should I just check my current one and try to see the color? (I can see that one in the picture above is blue, should I be able to see mine as easily, too?)
 

adamant628

Veteran Member
Joined
Jul 20, 2009
Location
Columbus, OH
TDI
2003 Jetta Wagon GLS
CoolAirVw said:
Pull the clip. Have the new o-ring ready on the sensor with some kind of Pick tool to yank out the old o-ring. Then pull out the sensor and o-ring quickly, then reinstall the new one quickly.

Point here is to try to loose as little antifreeze as possible.
Is the antifreeze going to be flowing out here?
 

paramedick

TDIClub Enthusiast, Vendor
Joined
Jul 29, 2001
Location
Versailles, Kentucky
TDI
2015 Audi Q5 TDI
adamant628 said:
Is the antifreeze going to be flowing out here?
Yes, copiously. A couple of hints. Jack the car up on the drivers side. Limits the loss. Removing the airbox and accordion hose opens up the area nicely. Some folks put a small garbage bag under the CTS to catch the antifreeze that flows out. After new sensor is in place, you can snip a corner off the bag, and let caught coolant flow back into open reservoir.

New coolant temp sensor will be green. Your old sensor is probably black. The blue sensors are used only on the early ALH engines.
 

adamant628

Veteran Member
Joined
Jul 20, 2009
Location
Columbus, OH
TDI
2003 Jetta Wagon GLS






It looks black, but also kind of rectangular (though rounded). So do I want the blue or green!?

Also, does the connector look a little lose to you?

Edit, comparing to the above picture, I guess it is the connector that is round.
 

Anomie

Veteran Member
Joined
Jul 4, 2009
Location
San Diego
TDI
09 Jetta DSG
Blue is not available; GREEN is the color of the new ECT. If you order one, double check that your seller of choice denotes "this is the newer ECT with green body" or something to that effect. Make sure it has a fresh o-ring. Use paramedick's method; his should save you a lot of time and effort. Be prepared for the coolant to almost jump out at you when you pull the ECT out. Things can and likely will get messy. :)
 

todhog

Member
Joined
Jul 19, 2008
Location
Peachtree City
TDI
05 Beetle
Hi, I got a check engine light the other day so I pulled into Autozone and had them scan it. It came back with a low coolant temp and bad coolant temp module. So I went to VW and paid the big bucks for parts and a gallon of pink coolant ($22.00). I changed the thermostat and the module with info I got here and everything seems to be OK except for two things.

First, when I pulled the thermostat out I lost a good amount of fluid so when I was done I filled the little tank all the way up figuring it would get sucked in. After idling for ten minutes and then driving a few miles the tank is still full. How do I get the coolant back into the system?

Second, how do I get rid of the check engine light now that everything is fixed?

BTW this is an 05 New Beetle.

Todd
 
Last edited:

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
todhog said:
After idling for ten minutes and then driving a few miles the tank is still full. How do I get the coolant back into the system?
How much coolant is left in the jug you bought from the dealer?
Did you mix the coolant at 50-50 before filling the cooling system?

todhog said:
Second, how do I get rid of the check engine light now that everything is fixed?
Some codes will clear after ~5 start/stop/warm-up/cool-down cycles.

Other codes need to be cleared with VCDS.

Tony
 

todhog

Member
Joined
Jul 19, 2008
Location
Peachtree City
TDI
05 Beetle
I only used enough to fill the tank. I figured I'd mix in some water when the tank got low. After letting it sit for a while it did suck some of the coolant out of the tank. I guess I'll drive it some and keep checking.

I'll watch the light too to see if it goes out soon. Thanks,

Todd
 

todhog

Member
Joined
Jul 19, 2008
Location
Peachtree City
TDI
05 Beetle
Update, I let my wife drive it to the store to try and get a good heat cycle and it overheated. Nothing like spending a day working on your car only to have it blow up:mad: .
 

todhog

Member
Joined
Jul 19, 2008
Location
Peachtree City
TDI
05 Beetle
Next update (feel like I'm talking to myself), went to pick up my car after letting it cool off all day and found the coolant tank empty. Filled it up and drove it home. Didn't over heat and the tank was only half full when I got home. I guess it just takes a while to get the cooling system full.

Todd
 

adamant628

Veteran Member
Joined
Jul 20, 2009
Location
Columbus, OH
TDI
2003 Jetta Wagon GLS
I am occasionally (less often than the P0118 code) getting a P0128 code, which doesn't even show up on Ross-Tech's wiki. It does however correspond to a code for other cars, I found it on a BMW forum, and a volvo forum. It is something about too low coolant temp signal. I assume since I get the P0118 code that it makes sense for it to be related. I guess I will be replacing the sensor eventually.
 

todhog

Member
Joined
Jul 19, 2008
Location
Peachtree City
TDI
05 Beetle
Final update, coolant level seems to have found it's own level and holding. Check enigine light went out today too. Guess its fixed.

Todd
 

dieselfuel

Veteran Member
Joined
Dec 28, 2008
Location
ohio
TDI
2003 Jetta TDI
I assume you checked the oil to make sure there isn't any coolant in the crankcase...?

Just a thought...
 

Anomie

Veteran Member
Joined
Jul 4, 2009
Location
San Diego
TDI
09 Jetta DSG
A failed head gasket can lead to cross contamination of the oil and cooling systems. That's all there is to it.
 

TonyJetta

Top Post Dawg
Joined
Sep 15, 2005
Location
Tucson, Az
TDI
'15 Jetta TDI SE / '06 Jetta TDI DSG Pkg0 / '96 Passat TDI
todhog, Anomie is talking about your overheating event. These aluminum cylinder heads are sensitive to overheating.

Take the minute and check oil. If it looks like normal oil...you dodged a bullet.

TOny
 

todhog

Member
Joined
Jul 19, 2008
Location
Peachtree City
TDI
05 Beetle
Oh I see. It didn't truly overheat. As soon as the red light came on and it beeped at my wife she pulled into a parking lot and shut it off. I picked her up and we left it to cool for about six hours and that's when it finally sucked new coolant out of the tank. I refilled it and it sucked about half of that out too which is about what I lost in the thermostat change. My problem I was trying to resolve was getting coolant into the system and the air out. Seems to have fixed itself and is running good.

Todd
 
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