[CO335D]

Hey there,

I am the new owner of a 2011 335D. I got my first SES light after only a couple months of ownership. I scanned the car with my BMWhat app, and received the following:

4BAC - Active reducing agent tank level sensor, signal.

I did some searching around other forums to see what I could find, and it seems there have been common issues with the Active DEF tank. It is my understanding that this tank is not serviceable, and may have to be replaced as an entire unit.

I was reading on another forum, and a post dated 4/7/2014 stated that BMW had issued a recall to replace the Active Tanks in our cars. Can anyone confirm this?

I have 66,7XX on my car now, and I do not have any extended warranty. Had I read all the crap that goes wrong on these things, I probably would of at the very least bought the CPO warranty.

Has anyone else encountered just this code? Is there anything I can try to clear it without having to replace the entire Active tank?

Any help is greatly appreciated.

[GreekboyD]

Now is your chance to do an EGR, SCR, DPF and other various alphabet deletes.

[CO335D]

I am absolutely on board to do them all, but it doesn't seem like they are 100% ready to go yet. I know 2deer has made a dpf delete pipe, and is currently working on a full exhaust. I want to wait until that is complete. I also read JR Auto's thread, and kind of want the coding and SpiderBOOT to be ready 100%. I don't want to jump the gun on any of it and be without a car.

I am very big into diesel performance. I have a 2001 Ford F250 that we swapped a 2006 5.9L Cummins into. It is built pretty stout and recently dynoed 916HP a few months ago. I can't wait to get all the emissions crap off this "clean diesel".

[floydarogers]

Originally Posted by CO335D

...
4BAC - Active reducing agent tank level sensor, signal.

I did some searching around other forums to see what I could find, and it seems there have been common issues with the Active DEF tank. It is my understanding that this tank is not serviceable, and may have to be replaced as an entire unit.

I was reading on another forum, and a post dated 4/7/2014 stated that BMW had issued a recall to replace the Active Tanks in our cars. Can anyone confirm this?

I have 66,7XX on my car now, and I do not have any extended warranty. Had I read all the crap that goes wrong on these things, I probably would of at the very least bought the CPO warranty.

Has anyone else encountered just this code? Is there anything I can try to clear it without having to replace the entire Active tank?

SIB 16 01 14. Bad temperature sensor in the tank. Came out May 1 2014, don't know what model years have the problem. If you're in the campaign, you should be able to get the entire new tank, which would fix your problem, too.

One thing to try is to drain your def tank(s), then flush them with water, then refill with DEF. Sometimes that's enough to remove the crystalization that's causing the problems.

[WreckerX5d]

Originally Posted by CO335D

I am absolutely on board to do them all, but it doesn't seem like they are 100% ready to go yet. I know 2deer has made a dpf delete pipe, and is currently working on a full exhaust. I want to wait until that is complete. I also read JR Auto's thread, and kind of want the coding and SpiderBOOT to be ready 100%. I don't want to jump the gun on any of it and be without a car.

I am very big into diesel performance. I have a 2001 Ford F250 that we swapped a 2006 5.9L Cummins into. It is built pretty stout and recently dynoed 916HP a few months ago. I can't wait to get all the emissions crap off this "clean diesel".

I'm surprised the universe didn't implode because of that swap.

[2deerwhistlers]

Originally Posted by CO335D

I am absolutely on board to do them all, but it doesn't seem like they are 100% ready to go yet. I know 2deer has made a dpf delete pipe, and is currently working on a full exhaust. I want to wait until that is complete. I also read JR Auto's thread, and kind of want the coding and SpiderBOOT to be ready 100%. I don't want to jump the gun on any of it and be without a car.

I am very big into diesel performance. I have a 2001 Ford F250 that we swapped a 2006 5.9L Cummins into. It is built pretty stout and recently dynoed 916HP a few months ago. I can't wait to get all the emissions crap off this "clean diesel".

You running compound turbos and dual cp3 pumps? That's some
Good power!

[Nushibo]

Originally Posted by CO335D

Hey there,

I am the new owner of a 2011 335D. I got my first SES light after only a couple months of ownership. I scanned the car with my BMWhat app, and received the following:

4BAC - Active reducing agent tank level sensor, signal.

I did some searching around other forums to see what I could find, and it seems there have been common issues with the Active DEF tank. It is my understanding that this tank is not serviceable, and may have to be replaced as an entire unit.

I was reading on another forum, and a post dated 4/7/2014 stated that BMW had issued a recall to replace the Active Tanks in our cars. Can anyone confirm this?

I have 66,7XX on my car now, and I do not have any extended warranty. Had I read all the crap that goes wrong on these things, I probably would of at the very least bought the CPO warranty.

Has anyone else encountered just this code? Is there anything I can try to clear it without having to replace the entire Active tank?

Any help is greatly appreciated.

Yes I have and the normal procedure for the dealer is to replace the tank sadly. You cant do much other than just clearing the code and ignoring it until you can do the Alphabet deletes lol. To clear it you can use BMWhat app and a bluetooth adapter, someone with an OBDII D-can cable, or a very good code reader with clear function. Id say BMwhat cause youre going to be using it alot lol

[Yozh]

Originally Posted by floydarogers

One thing to try is to drain your def tank(s), then flush them with water, then refill with DEF. Sometimes that's enough to remove the crystalization that's causing the problems.

This, but drive around with both tanks full of distilled water for a bit. I believe you get 100mi or so with a "wrong" urea (water) before you get a no start warning. You will get other NOx related codes though. Or just fill full with water and let it sit, then repeat.

[taibanl]

4BAC - P203A
Information saved in
DDE
Fault code
4BAC - P203A
Fault text
DDE: Reducing-agent active-tank fill-level sensor, signal: Sensor fault
Fault description
Monitoring of active tank level sensor. The diagnostic trouble code is logged when the physical sensor signal is between 35 % and 45 %.
Condition for fault identification
none
Condition for fault memory entry
Debounce (2000 ms)
Action in service
1. Check wires and plug connections.
2. If wiring and plug connections are OK:
3. Use the diagnostic system to check the fluid levels.
4. Replace the active tank.
Fault effect and breakdown warning
-
Driver information
Warning light:
MIL
Service instruction
Measure the resistance levels on the level sensor between reference (pin 1) and tank level 1-3 (pins 2-4). The tank must be empty for the measurement.
Nominal value with tank empty: 10 kOhm
Resistance levels in excess of 12 kOhms indicate a defective fluid-level sensor.

[Hoooper]

I've had it twice. Both times I filled the tanks with DEF and took the car for a nice g-loaded back country drive and cleared the code. The first time it went away for probably 10k miles before it came back. The second time it has not come back yet, probably 5-7k miles ago. I do like the idea of filling the tanks with water, driving hard, and then draining and replacing with DEF. Clean water should really clean any crystallized DEF off nicely. Don't go too far though, hate to be stuck somewhere if you need to shut the car off for some reason.

[TDIwyse]

Originally Posted by CO335D

...I have a 2001 Ford F250 that we swapped a 2006 5.9L Cummins into. It is built pretty stout and recently dynoed 916HP a few months ago...

Love everything about that.

[Mark M]

How do you drain the def tanks, is there a petcock valve or something under there to allow complete drainage?

[CO335D]

Originally Posted by 2deerwhistlers

You running compound turbos and dual cp3 pumps? That's some
Good power!

Yessir. That 916 was with a blown head gasket actually. It is fire ringed now, so hopefully I can get it on another dyno sometime soon. I'm running an S366 over an S488. It's been a pretty good set up, and pretty streetable.

Here she is:



Yes... I am a huge OU fan.

Anyways, hopefully I qualify for that Service Bulletin. Is the best way to determine that to just call any of the local service centers? Sorry for the ignorance, but I can't remember the last time I've owned anything that had to go to the dealer to be worked on.

[2deerwhistlers]

Originally Posted by CO335D

Yessir. That 916 was with a blown head gasket actually. It is fire ringed now, so hopefully I can get it on another dyno sometime soon. I'm running an S366 over an S488. It's been a pretty good set up, and pretty streetable.

Here she is:



Yes... I am a huge OU fan.

Anyways, hopefully I qualify for that Service Bulletin. Is the best way to determine that to just call any of the local service centers? Sorry for the ignorance, but I can't remember the last time I've owned anything that had to go to the dealer to be worked on.

Nice! I've got a p-pumped 24v with an s366 over an s480.. Fire ringed and studs everywhere.. Been abusing the old girl for 8 years.. Just change the oil every 1000 miles

[CO335D]

Originally Posted by 2deerwhistlers

Nice! I've got a p-pumped 24v with an s366 over an s480.. Fire ringed and studs everywhere.. Been abusing the old girl for 8 years.. Just change the oil every 1000 miles

Yeah, she is back home in Texas for the winter right now... but I'll be down there for Christmas and will change the oil and filter again. I just painted the frame and motor, and wasn't really looking forward to it sitting in these winters up in CO. I don't have room for it in the building I live in. I love that damn truck though, and definitely drive it like I stole it. I have always been a fan of the 12V and 24V from a simplicity standpoint, but ever since EFI live was a possibility I've really liked the clean power these CRs can make.

[2deerwhistlers]

I hear ya on the efi live! So you live in a garage too!? Haha

[CO335D]

Originally Posted by 2deerwhistlers

I hear ya on the efi live! So you live in a garage too!? Haha

Unfortunately... I'm in downtown Denver. I love it here, but miss my parking situation in Texas a lot. I had the truck up here this summer, and it was a blast. The turbos definitely didn't like the altitude though.

[m9bm]

I had the same code a month ago. I live in California, where the emissions part of all vehicles is required to be covered to 70000 miles.

I was at 50000 when it threw the code 4BAC. Dealer replaced the entire tank under warranty at no cost to me.

However I also have 7year/100k mile BMW gold warranty. If it wasn't covered by the emissions warranty I would have had to pay the $50 deductible.

[CO335D]

Originally Posted by m9bm

I had the same code a month ago. I live in California, where the emissions part of all vehicles is required to be covered to 70000 miles.

I was at 50000 when it threw the code 4BAC. Dealer replaced the entire tank under warranty at no cost to me.

However I also have 7year/100k mile BMW gold warranty. If it wasn't covered by the emissions warranty I would have had to pay the $50 deductible.

I'm calling a service center after work today to see if my car is covered under the SIB posted above. Fingers crossed...

[m9bm]

As I was told, it would be a $2-3k repair if not covered..

If it isnt covered I would attempt to get BMW NA involved and possibly good will it.
Always worth a shot.

good luck

[taibanl]

Originally Posted by CO335D

I'm calling a service center after work today to see if my car is covered under the SIB posted above. Fingers crossed...

Please report back

[What_A_D]

Originally Posted by Mark M

How do you drain the def tanks, is there a petcock valve or something under there to allow complete drainage?

bump


does anybody know how to drain the def tanks?