UNOFFICIAL Adblue Heater Element Failure Thread

Yankinwaoz

Veteran Member
Joined
Jun 17, 2005
Location
San Diego, CA
TDI
2012 Passat SE
VW replaced my AdBlue heating element under warranty for free. My car has 110323 miles, and is from 2012. So it cost me nothing. I am very pleased with their response.

The dealer did this in one day. I dropped it off Tuesday morning and it was ready Tuesday afternoon.

The repair paperwork says "Found 1 DTC for Adblue tank heater element control circuit low. Checked wiring and connections. No problems found. Per tech bulletin #26-16-05 replaced AdBLue header element. Performed leak test and reset ECM."
 

Mark_J

Veteran Member
Joined
Aug 17, 2003
Location
Deer Park, Washington
TDI
2015 TDI Passat SEL Premium, 2017 Fiat Spider, 2017 Ford F350 6.7 Diesel crew cab PU, 2016 Harley Trike, 2016 Tesla Model X P90D (I know went to the dark side)
2013 Passat SEL Premium, 46,000 milesgot the CEL light yesterday. Cleared it for giggles. Chatted with VW and mine is covered under the extended warranty. So if it comes back will book and appointment.

1 Fault Found:
9656 - Control Circuit for Reductant Tank Heating
P202B 00 [237] - Short to GND
MIL ON - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 75253 km
Date: 2017.02.22
Time: 04:56:42

Engine speed: 1483.50 /min
Normed load value: 71.0 %
Vehicle speed: 78 km/h
Coolant temperature: 44 °C
Intake air temperature: 28 °C
Ambient air pressure: 1020 mbar
Voltage terminal 30: 14.120 V
Unlearning counter according OBD: 40
Outside air temperature: 1.0 °C
Exhaust gas temperature sensor 4: 285.6 °C
Sensor for reducing agent tank temperature: temperature: 4.8 °C
Heat circuit 2 for reduc. agent meter. system: act. voltage: 136.6 mV
Heat circuit 2 for reduc. agent meter. system: act. voltage: 136.6 mV
Heat circuit 1 for reduc. agent meter. system: act. voltage: 586.2 mV
 

rustycat

Veteran Member
Joined
Dec 27, 2012
Location
seattle
TDI
2015 passat sel
51K on my Nov 2013 SEL and just had the repair done. I had a great experience with the dealer and for that reason I'll give that dealership a high recommendation. The Dealer is VW of Olympia. BTW, I've tried 4 other dealers in the Seattle area and could not recommend any of them.
 

Mark_J

Veteran Member
Joined
Aug 17, 2003
Location
Deer Park, Washington
TDI
2015 TDI Passat SEL Premium, 2017 Fiat Spider, 2017 Ford F350 6.7 Diesel crew cab PU, 2016 Harley Trike, 2016 Tesla Model X P90D (I know went to the dark side)
Wish VW of Olympia was closer. I live in Deer Park Wa, N of Spokane but work in NW Wa. so I am close to the Canadian border.
 

Fastbird

Veteran Member
Joined
Oct 12, 2013
Location
Fort Wayne, IN
TDI
2012 Passat SEL, 2015 Sportwagen SEL
Just had my throw a P202B code yesterday morning.

2012 SEL
115xxx miles

If it pops again I'll get it to the dealer for the fix.
 

shak911

Veteran Member
Joined
Nov 2, 2010
Location
toronto
TDI
2004 Jetta TDI-372000KM
Just had my throw a P202B code yesterday morning.

2012 SEL
115xxx miles

If it pops again I'll get it to the dealer for the fix.
You're very close to the expiry mileage of the extended warranty of 120,000. miles.
my code (p202 would return 2 restart after reset.)
 

Rico567

Top Post Dawg
Joined
Jun 13, 2003
Location
Central IL
TDI
2013 Passat TDI SEL Premium (Turned in 7/7/18)
By all means get in to the dealer and get the code documented. Even if the code goes away before you get there, at least there'll be a record of it and I'd think you'll have a good shot at a free repair even if you go over 120K.
 

Fastbird

Veteran Member
Joined
Oct 12, 2013
Location
Fort Wayne, IN
TDI
2012 Passat SEL, 2015 Sportwagen SEL
Sitting at the dealer right now. Already have a positive diagnosis, appointment for next Wednesday to have the repair kit installed. They're even washing my car for me right now.
 

TDIpstick

Member
Joined
May 17, 2007
Location
Florida
TDI
02 jetta ALH "upgraded" to 12 Passat CKRA
Waiting to pass "go" and collect my $21k

2012 Passat
CEL
79,839 miles
3 Faults Found:
9688 - Reductant Tank Temperature Sensor
9687 - Reductant Tank Temperature Sensor
15733 - SCR NOx Catalyst Bank 1
no symptoms, no repairs yet, going to see if dealer will fix it under warranty, no risk of freezing in FL
 

Tinkertoy

Active member
Joined
Aug 17, 2014
Location
Florida
TDI
'17 passat SEL 1.8t gasser, '13 passat se dsg
my pump crapping out was part of the reason i took the buyback offer. i backed in to something that must have jarred the pump, I was getting a temp out of range or low pressure code (I forgot what is was exactly). it was not covered under warranty.

that repair, along with the timing belt, tires, brakes, deductible for bodywork, etc would have hurt bad.

I applied the restitution money towards a new SEL gasser, which I love.
 

roni024

Veteran Member
Joined
Mar 31, 2007
Location
Syracuse, NY
TDI
2015 Passat TDI SEL DSG
My MIL on my 13 DSG SE lit up over the weekend. Scanned with VCDS and found code P202A: Reductant Tank Heater Control Circuit. Car has roughly 135k on it, so warranty coverage is not expected.

I have suspicion that the failure is most likely caused by crystallized urea building up somewhere on the AdBlue heating element, level sensors, or inside the pump itself. I'm planning to attempt repair to see if I can dissolve these crystals and restore functionality. My plan is to siphon and remove as much DEF fluid as possible from the tank, then fill to brim with heated (maybe boiled) distilled water with some isopropyl alcohol added in (say 1/2 cup alcohol to gallon of water). I'll immediately take the car on a little roadtrip (1-2 hours highway driving), then empty the water and refill with DEF.

Has anyone tried something similar and can report your findings? What are the risks involved with running the car with water instead of DEF for a short time?
 

redline_r

Member
Joined
Mar 14, 2003
Location
Atlanta, GA
TDI
12 Touareg
Did you do this?
I'm so curious as to what's causing this part to malfunction all the time, and haven't found that explained anywhere yet.
My MIL on my 13 DSG SE lit up over the weekend. Scanned with VCDS and found code P202A: Reductant Tank Heater Control Circuit. Car has roughly 135k on it, so warranty coverage is not expected.
I have suspicion that the failure is most likely caused by crystallized urea building up somewhere on the AdBlue heating element, level sensors, or inside the pump itself. I'm planning to attempt repair to see if I can dissolve these crystals and restore functionality. My plan is to siphon and remove as much DEF fluid as possible from the tank, then fill to brim with heated (maybe boiled) distilled water with some isopropyl alcohol added in (say 1/2 cup alcohol to gallon of water). I'll immediately take the car on a little roadtrip (1-2 hours highway driving), then empty the water and refill with DEF.
Has anyone tried something similar and can report your findings? What are the risks involved with running the car with water instead of DEF for a short time?
 

bustNfuel

Veteran Member
Joined
Sep 7, 2002
Location
Raleigh, NC
TDI
Sold: 13 Passat SEL TDI
AdBlue heater replaced under TSB 2041110 after CEL. Codes P205B and P20EE.

Free DEF fill.

Drive more, worry less!
 

jafische

Veteran Member
Joined
Dec 1, 2012
Location
Pace, FL
TDI
2013 (A3) TDI SEL Premium (Reflex Silver / Moonrock)
Did you ever get an answer to this?



I tried wiring in the resistor by cutting off the black and white wires and looping it back to the car but my car keeps throwing the P202B fault after 2 drive cycles. In the photos provided in the original post it looks like there are 2 resistors wired in.

Can anyone clarify this? I've already dropped my DEF tank 2 times to try this fix.
The 202B is the heater control circuit.
The 205B is the Temperature Sensor Circuit Range/Performance.

I wonder if you would have wired a 3ohm resistor to the red/white (heater), that is that where you needed to trick the car?
 

enpassat

New member
Joined
Jul 11, 2021
Location
Northern California
TDI
2014 Passat
2014 Passat TDI SEL
57246 miles
CEL with a P205B

CEL would come on (sometimes) when the vehicle was cold and RPMs went over 2000. I live on a hill, so while coming down in the the morning it would often downshift and the CEL would (about half the time) come on. No drivability issues, just an annoying light. If cleared, it would stay off until the next cold start. If I could keep the RPMs under 2000 while the engine warmed, no CEL.

P205B on my scanner read: "Reductant Tank Temperature Sensor, Circuit Implausible Signal" and shows the vehicle speed was 158 mph.

I swear, officer, I couldn't have been going over 120.

VW dealer found an "an open circuit in tank temp sensor", then drained the ad blue tank and replaced heater element and all gaskets and seals and reinstalled tank and topped off.

All under warranty, but for me it ends June 2024 or at 120,000 miles. Gotta do some roadtripping I guess.

Thanks to all who post on this forum. This is my first TDI and so it's great to be able to access the repository of knowledge and experience that's here.
 

jafische

Veteran Member
Joined
Dec 1, 2012
Location
Pace, FL
TDI
2013 (A3) TDI SEL Premium (Reflex Silver / Moonrock)
2014 Passat TDI SEL
57246 miles
CEL with a P205B

CEL would come on (sometimes) when the vehicle was cold and RPMs went over 2000. I live on a hill, so while coming down in the the morning it would often downshift and the CEL would (about half the time) come on. No drivability issues, just an annoying light. If cleared, it would stay off until the next cold start. If I could keep the RPMs under 2000 while the engine warmed, no CEL.

P205B on my scanner read: "Reductant Tank Temperature Sensor, Circuit Implausible Signal" and shows the vehicle speed was 158 mph.

I swear, officer, I couldn't have been going over 120.

VW dealer found an "an open circuit in tank temp sensor", then drained the ad blue tank and replaced heater element and all gaskets and seals and reinstalled tank and topped off.

All under warranty, but for me it ends June 2024 or at 120,000 miles. Gotta do some roadtripping I guess.

Thanks to all who post on this forum. This is my first TDI and so it's great to be able to access the repository of knowledge and experience that's here.
Install external thermistor unless you live in Canada. I have a 2013 and have been through 4 adblue tanks under VW warranties.
 

Lex Tdi

Veteran Member
Joined
Oct 4, 2016
Location
Lexington ky
TDI
2013 Passat
Install external thermistor unless you live in Canada. I have a 2013 and have been through 4 adblue tanks under VW warranties.
Good grief... there is a good way to be done with all that;). The past 100k trouble free miles have been amazing!
 

Windkid

New member
Joined
Apr 20, 2022
Location
Ogden Utah
TDI
14
My MIL on my 13 DSG SE lit up over the weekend. Scanned with VCDS and found code P202A: Reductant Tank Heater Control Circuit. Car has roughly 135k on it, so warranty coverage is not expected.

I have suspicion that the failure is most likely caused by crystallized urea building up somewhere on the AdBlue heating element, level sensors, or inside the pump itself. I'm planning to attempt repair to see if I can dissolve these crystals and restore functionality. My plan is to siphon and remove as much DEF fluid as possible from the tank, then fill to brim with heated (maybe boiled) distilled water with some isopropyl alcohol added in (say 1/2 cup alcohol to gallon of water). I'll immediately take the car on a little roadtrip (1-2 hours highway driving), then empty the water and refill with DEF.

Has anyone tried something similar and can report your findings? What are the risks involved with running the car with water instead of DEF for a short time?
Did this work?
 

Tom in PT

Veteran Member
Joined
Jun 7, 2017
Location
Twilight Zone, WA State
TDI
2005 Passat sedan - SOLD; 2013 Passat DSG; both purchased new
Thanks for posting that! I have not had this code (yet) but I may just take it apart like he shows just to clean it and keep it happy. Gotta love those "special VW tools."
 
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