Back ground info: 2009 3.0L TDI, highline, 122,000 km
When the temps dropped below freezing this year I got an MIL on the dash. My buddy pulled the code to reveal P202A-Reductant tank heater circuit Open. So after doing some reading on here I concluded that my adblue tank heater was dead. I couldn't find info on how to replace it myself, but thought it looked simple enough. I picked up the heater repair kit (essentially the heater without the pump), and a couple jugs of adblue for just under $400 from my local VW.
The kit included the heater, locking ring nut, seal, o-rings, integrated level sensor, three socket head cap screws, hose connector, and zip ties.
I did this job on my back on the floor of my garage with nothing more than a single floor jack (and a jack stand).
I started out by siphoning as much of the adblue out of the tank through the fill port, only to make it lighter for me to work on the tank (has to be dropped). I might add that this job would have been much much easier if only VW had made the top of the tank accessible from under your spare tire! In nut shell, I'd have to lower the rear exhaust and muffler, remove the heat sheild, lower the adblue tank, and replace the heater from the top of the tank. Here goes...
Next I jacked up the back passenger side of the Touareg. I loosened the two bolts on the exhaust pipe connector that connects the back half of the exhaust piping. This would allow for some flex when I lower the rear exhaust. I also unbolted the two bolts on the hanger just behind the connector. Both of these are near our infamous drive shaft carrier bearing.
Next I unbolted the two rear exhaust hangers located at the rear corners of the muffler. Then I just lowered the muffler until it rested on the floor of the garage.
Then I took the nuts off of the heat shield (approx 6), and removed it all together. Now I could see the underside of the plate that holds the adblue tank in place. The tank actually is bolted to this plate.
I removed the 4 nuts that hold the plate in place, and began lowering the plate (and tank). I quickly found that the insulation on the tank wouldn't allow it to pivot out (back end down first). The front end of the plate was hanging up on the rear anti-sway bar.
To give myself more room, I unbolted the two clamps (2 bolts each) to allow the anti-sway bar to lower about 7 cm. This allowed the plate and tank to lower out of the body. There are a number of electrical connectors to unplug, but luckily they are all sized differently so you can't make a mistake. There was also a single hose connection to remove by squeezing the white collar around the connection. I also had to cut a couple zip tie cable connectors, but don't worry because new ones come with the kit.
Finally the tank was free. It still had the metal plate on the bottom of it, but that really didn't mater. I removed the top foam insulation, and was looking at the pump assembly.
Next I unscrewed the three socket head cap screws, and pulled the hose off of the pump by pulling straight up on the plastic connector. I just set the pump aside on a clean towel.
Then the locking ring had to be spun off by hand (was super tight!). I couldn't get it without using a piece of wood for leverage (see pic). Then I pulled the seal free, and found that you have to turn the heater assembly about 5 degrees counter clock-wise to unlock it from the bottom of the tank. Then it lifted right out.
I first put the new seal into the tank, and then put the new heater assembly into the tank, lining up the tabs on the bottom (can't mistake because they're asymetrical). Twist the assembly about 5 degrees clock-wise so that it locks to the bottom of the tank (note that there is an arrow on the top of the heater assembly that should line up with an arrow on the top of the tank when locked.
Then thread the new locking ring on as tight as you can by hand. I then replaced the small o-ring on the bottom of the pump with the one from the kit. There is a second seal in the kit, but oddly enough there was already a new seal on the top of the heater assembly lid.
I then pressed the pump onto the lid, lining up the three screw holes. I inserted and tightened the three new socket head cap screws (also in the kit). The hose had to be reconnected to the pump unit (hard press from above). I was able to reuse the existing one, but also had a new one in the kit just in case.
Then it was a matter of just reconnecting all of the electrical connectors, and stepping through everything in reverse order. Don't forget to refill your adblue tank!
Sorry the pics weren't better, but I only thought of taking pics to ensure I put things back in the right place.
I hope this helps anyone else who might have to tackle this job.
When the temps dropped below freezing this year I got an MIL on the dash. My buddy pulled the code to reveal P202A-Reductant tank heater circuit Open. So after doing some reading on here I concluded that my adblue tank heater was dead. I couldn't find info on how to replace it myself, but thought it looked simple enough. I picked up the heater repair kit (essentially the heater without the pump), and a couple jugs of adblue for just under $400 from my local VW.
The kit included the heater, locking ring nut, seal, o-rings, integrated level sensor, three socket head cap screws, hose connector, and zip ties.
I did this job on my back on the floor of my garage with nothing more than a single floor jack (and a jack stand).
I started out by siphoning as much of the adblue out of the tank through the fill port, only to make it lighter for me to work on the tank (has to be dropped). I might add that this job would have been much much easier if only VW had made the top of the tank accessible from under your spare tire! In nut shell, I'd have to lower the rear exhaust and muffler, remove the heat sheild, lower the adblue tank, and replace the heater from the top of the tank. Here goes...
Next I jacked up the back passenger side of the Touareg. I loosened the two bolts on the exhaust pipe connector that connects the back half of the exhaust piping. This would allow for some flex when I lower the rear exhaust. I also unbolted the two bolts on the hanger just behind the connector. Both of these are near our infamous drive shaft carrier bearing.
Next I unbolted the two rear exhaust hangers located at the rear corners of the muffler. Then I just lowered the muffler until it rested on the floor of the garage.
Then I took the nuts off of the heat shield (approx 6), and removed it all together. Now I could see the underside of the plate that holds the adblue tank in place. The tank actually is bolted to this plate.
I removed the 4 nuts that hold the plate in place, and began lowering the plate (and tank). I quickly found that the insulation on the tank wouldn't allow it to pivot out (back end down first). The front end of the plate was hanging up on the rear anti-sway bar.
To give myself more room, I unbolted the two clamps (2 bolts each) to allow the anti-sway bar to lower about 7 cm. This allowed the plate and tank to lower out of the body. There are a number of electrical connectors to unplug, but luckily they are all sized differently so you can't make a mistake. There was also a single hose connection to remove by squeezing the white collar around the connection. I also had to cut a couple zip tie cable connectors, but don't worry because new ones come with the kit.
Finally the tank was free. It still had the metal plate on the bottom of it, but that really didn't mater. I removed the top foam insulation, and was looking at the pump assembly.
Next I unscrewed the three socket head cap screws, and pulled the hose off of the pump by pulling straight up on the plastic connector. I just set the pump aside on a clean towel.
Then the locking ring had to be spun off by hand (was super tight!). I couldn't get it without using a piece of wood for leverage (see pic). Then I pulled the seal free, and found that you have to turn the heater assembly about 5 degrees counter clock-wise to unlock it from the bottom of the tank. Then it lifted right out.
I first put the new seal into the tank, and then put the new heater assembly into the tank, lining up the tabs on the bottom (can't mistake because they're asymetrical). Twist the assembly about 5 degrees clock-wise so that it locks to the bottom of the tank (note that there is an arrow on the top of the heater assembly that should line up with an arrow on the top of the tank when locked.
Then thread the new locking ring on as tight as you can by hand. I then replaced the small o-ring on the bottom of the pump with the one from the kit. There is a second seal in the kit, but oddly enough there was already a new seal on the top of the heater assembly lid.
I then pressed the pump onto the lid, lining up the three screw holes. I inserted and tightened the three new socket head cap screws (also in the kit). The hose had to be reconnected to the pump unit (hard press from above). I was able to reuse the existing one, but also had a new one in the kit just in case.
Then it was a matter of just reconnecting all of the electrical connectors, and stepping through everything in reverse order. Don't forget to refill your adblue tank!
Sorry the pics weren't better, but I only thought of taking pics to ensure I put things back in the right place.
I hope this helps anyone else who might have to tackle this job.
