How to: Replacing the Adblue Heater & Temp Sensor Module - Page 5

pridyuk · January 4th, 2016, 23:33

Hello, I have a 2013 passat tdi with 30k miles, and I have had a P205c (reductant tank temp sensor) CEL code for a few months now but really dont feel like spending another $600+. This past weekend my wife took the car to the dealership to do the 23N5 ecm update and as soon as she picked up the car, the display showed an add blue warning saying that i have 200 miles left to go (although the add blue tank is completely full). Is this mile countdown due to the cel code or a different issue? Is there anything i can do to reset it? This car has been a nightmare for us.
Please help

r90sKirk · January 7th, 2016, 09:30

Quote:

Originally Posted by TheGrove

You don't need the whole tank unfrozen. As I remember the pickup is next to the heater so just a short amount of time will thaw enough to start injecting. As you and others noted it probably doesn't start injecting right away. There is a warmup procedure the car follows that is temperature dependent. I would believe that when it is cold enough extra fuel is injected to reduce the NOx and also get the engine warmed up quicker. Another item if you listen to the car when you shut it off you can her the pump sucking the DEF back into the tank so the lines are clear and nothing is in them to freeze. The lines are also heated so the DEF will flow to the injectors once it is started to be pumped.

So, we ARE assuming that the DEF freezes when the car sits in very cold weather then?

I'm just looking for a concensus here.

Kirk

aullein · January 8th, 2016, 11:46

7L6-198-970A And 7P6-198-970A. Can anyone tell me the difference ?? I know 7L and 7P are the body codes for the gen1 and gen2 touaregs if that's what it might be. Wondering if one might be more updated and last longer than the other ? Looks like everyone on here that did the fix went with the 7L part#.

CNGVW · January 9th, 2016, 12:27

The pump has the heater right at the bottom of the suck tube in a small camber. The line to the injector at the first cat is not heated. What dos happen is when the car is shut off the pump reverses and sucks addblue and hot air back to the pump clearing the line for the next time.
I am shore the pump heater knows how cold it is so if it is frozen it will heat till it has unfrozen the chamber and then inject. When the key is off it will pull the warmed Addblue back and hot air to warm the tank for the next time.

Originally Posted by TheGrove View Post
You don't need the whole tank unfrozen. As I remember the pickup is next to the heater so just a short amount of time will thaw enough to start injecting. As you and others noted it probably doesn't start injecting right away. There is a warmup procedure the car follows that is temperature dependent. I would believe that when it is cold enough extra fuel is injected to reduce the NOx and also get the engine warmed up quicker. Another item if you listen to the car when you shut it off you can her the pump sucking the DEF back into the tank so the lines are clear and nothing is in them to freeze. The lines are also heated so the DEF will flow to the injectors once it is started to be pumped.

Quote:

Originally Posted by r90sKirk

So, we ARE assuming that the DEF freezes when the car sits in very cold weather then?

I'm just looking for a concensus here.

Kirk

craigpaul2000 · January 15th, 2016, 13:30

Thank you kindly for the awesome write-up. Simple job, 2 hours being extremely cautious.

Couple notes: The arrow on the large ring has no meaning. The ring is 100% symmetrical and it will go on as the threads allow. The VERY important thing is to align the insert molded screw, on the top of the heater assy, that holds the module, exactly where the rightmost hash mark is. This will ensure the module nipple is protected as you re-assemble the tank to the vehicle. I just dis-assembled the old one, took pictures of where it was and lined the new one up the same orientation.

Finally, please someone tell me the bag of random plugs and other stuff is not needed. I know I didn't remove anything like that so I cannot figure out why they are included.

Again, thanks for the walkthrough

zocalo · January 22nd, 2016, 18:18

Forgive if I have missed a post in these pages, but I'm a bit in the dark here. The AdBlue heater/pump is part of the emission package, or so I believed. I recently had this replaced by the dealer under that premise. I took in a scan from the VAG-COM, (engine light still on) with this issue late last year. They did caution me that if they didn't get the same result it would cost me to check. However, they confirmed and ordered the parts and replaced it (took 3 weeks to get the parts). No charges. My base warranty is long over (since I have a 2012 purchased in 2011). Is this something that maybe stringent CA emission laws cover for a longer period? Like I said, I might have missed a post.

Rico567 · January 23rd, 2016, 05:39

Quote:

Originally Posted by zocalo

Forgive if I have missed a post in these pages, but I'm a bit in the dark here. The AdBlue heater/pump is part of the emission package, or so I believed. I recently had this replaced by the dealer under that premise. I took in a scan from the VAG-COM, (engine light still on) with this issue late last year. They did caution me that if they didn't get the same result it would cost me to check. However, they confirmed and ordered the parts and replaced it (took 3 weeks to get the parts). No charges. My base warranty is long over (since I have a 2012 purchased in 2011). Is this something that maybe stringent CA emission laws cover for a longer period? Like I said, I might have missed a post.

There appear to have been different experiences with this issue, with some not getting the failure of this system covered, while you did. I think a good working hypothesis might be that the CA emissions warranty is involved, but I don't know for sure.

maf007 · February 14th, 2016, 07:41

Great writeup and thanks to all contributors.
I had a 202B, bought the Toureg kit ( http://www.expressoemparts.com/oe-volkswagen/7l6198970a) and the installation went slowly but smoothly. I didn't disconnect the harness/hose under the car, but I did pop the zip ties out of the frame to give me a little extra length. Removing the bumper cover was worth the effort for me.
The tank bolts are 13mm, so I used the 13mm socket I bought in 1977 for repairing my '67 Bug!

Big Red · February 17th, 2016, 16:56

Guess I need to use my $500 dealership card on this.

VeeDubTDI · February 17th, 2016, 17:37

Quote:

Originally Posted by Big Red

Guess I need to use my $500 dealership card on this.

I would wait until after you know whether A.) diesel gate compliance will force VW to fix existing AdBlue issues such as this, and B.) you are going to comply with a diesel gate recall.

I see no reason to repair this right now unless you're in an area that is subjected to sub-zero temperatures and you experience AdBlue freezing issues.

maf007 · February 18th, 2016, 08:15

^^^ Agree. My CEL has been on a while, but I've been able to park in a heated garage this winter. I fixed it after returning from 4000 mile trip to FL only because I might head to Canada within the next month. Otherwise I'd have ignored it.

heykw · February 26th, 2016, 12:56

Quote:

Originally Posted by silvrmax04

I replaced the module and all is good now. The add fluid wentbawaynin about 3-5 miles. Over 50 miles now and back to normal. I believe the module is actually a pump. If your hose is loose or not on it will leak and you will see the white crystal everywhere. Check all your wiring connections too.

What hose pics please

Big Red · February 26th, 2016, 18:44

Quote:

Originally Posted by maf007

^^^ Agree. My CEL has been on a while, but I've been able to park in a heated garage this winter. I fixed it after returning from 4000 mile trip to FL only because I might head to Canada within the next month. Otherwise I'd have ignored it.

It's unfortunate my wife drives the car. Just totally uncomfortable driving with the check engine light. Will likely be doing the replacement this weekend.

Big Red · February 28th, 2016, 07:17

I ended up doing this job yesterday! The write up was clear and very helpful. I pulled the bumper cover all the way off so I didn't risk accidentally popping a fastener or scratching paint.
I had some trouble removing the old unit while doing the 15 degree counter clockwise turn. I had to wiggle back and forth to get it to move.

If folks have not worked with these newer style electrical fasteners before, it would be good to point out the colored piece of the plug needs to be pulled straight out 1-2mm, then Squeezed to release the plug.

I used about 2 hrs to do the whole job as well taking my time, referencing the write up and picking up when done.

I was lucky to be at 400 miles on my Ad Blue so there wasn't much left and I didn't end up removing any fluid.

mnelsonx · March 21st, 2016, 10:52

My CEL has been on for about 9 months for P202b, so I finally did this job over the weekend. Couldn't have done it nearly as quickly without the guide (and would probably would have broken things), I really appreciate the time it took to put this guide together.

After using the dealership "Goodwill" package (plus a significant amount of the general Goodwill card) to buy this part, the amount of actual goodwill VW has earned with it is zero. VW really should be covering this issue and going back after the OEM for the significant number of failures.