# OBD-II Diagnostic Trouble Code P203A



## Flyingman (Sep 13, 2009)

Hmmm, so they had to replace the DEF tank. I assume the pump, sensors, levels, etc... are easier to fix by replacing the entire unit.

We all know that will cost a pretty penny after warranty expires. Certainly this is one area of the 335D that will be subject to failure.

I guess I'll have to bring mine in before the warranty expires as well. The code is triggered but I currently have no SES or other indication on the OBC, just the Garmin Ecoroute.


----------



## Flyingman (Sep 13, 2009)

While I had my car in to get the rear wheel rim fixed, I asked them to check the P203A code it had thrown.

I don't know what they found but when I got it back the code was no longer showing on my Ecoroute HD. So I assume it resolved itself.:dunno:

I had to reset the Ecoroute HD that plugs into the OBCDII port, so that may have reset it as well. The car itself was not showing the SES or code for a long time, just couldn't get the Ecoroute to reset it.


----------



## GreekboyD (Jan 25, 2012)

Flyingman said:


> Hey, you have like 145k miles. Not much you can complain about. Sounds like some of your problems are emission related, shouldn't some of it still be under warranty?:dunno:
> 
> I think you may have the vehicle with the highest miles on this forum best I can tell.:thumbup:


I was told that after I did the recall last week, the warranty resets on the emissions system to 8 years/160,000 kms...whichever comes first.


----------



## Flyingman (Sep 13, 2009)

It's back again. P203A code. SES light came on for about 2 days, then is gone. Garmin still registers it and won't clear it.

Guess I'll have to go back for this specific item.

Seems like most of us with problems are related to the emission controls.:tsk::thumbdwn:


----------



## stickyplus (Dec 12, 2013)

Just want to share my experience on the similar situation.

I took my car to the regular gas station to refill the diesel tank last Wednesday. the flow of gas was extremely slow and stop automatically without even half tank. went home and think to refill it some other time. 
My wife called and told me that Check Engine light went off the very next day. After getting the OBD scanner check the error code, I got P203c pending and P205a logged. after doing research on the internet and also found this thread, I know this is something related to the DEF tank. luckily, I have a bottle of DEF from my previous service and the SA was kind enough to have me keep it. I put it in and drove around yesterday and use the OBD scanner to check the error code again, it was cleared.  This morning, I noticed the check engine light went off.. 

It seems like the code are related to the lack of the DEF and I called BMW dealer in Fremont and got a 2.5 gallon DEF for $26.00 + tax. The Tank took about half of the container and I put the rest in to the passive tank on the right of the engine.

If you live around the Bay area and need to buy parts, especially the oil and DEF, the Fremont BMW dealer is a good choice. They sell these at fair market price, highly recommand it.

BTW, if you plan to add the DEF yourself and don't know how, here is the good video to show you. 



 thank you for sharing your post, AskTheCarExperts.

Good luck.


----------



## rhdmd (Dec 24, 2013)

I have a 2009 335D, 45700mi. Never have any problem. Regular warranty is out. The SES light came on twice and went off, then it came on a third time and stayed on. Took it into the dealer and they said that the first two SES light was from a Mass Airflow sensor fault and the third is from the SCR active tank sensor assembly. It sounds very much like the problems you all are talking about. These are clearly part of the emission system. It should be covered under the California 7 year/70000 miles emission warranty. But they told me they checked the list of parts under the warranty and did not find them on the list so it is not covered by the warranty. 
Someone on the forum has said that the dealers do not know anything about the emission warranty for the diesel cars because there are so few of them and we should deal with the BMW NA. I tried to talk to the customer relations agent and she said that I need to talk to the dealer. They seem to push the responsibility to each other. What should I do? Anybody here had any success getting this covered by the emissions warranty? Here did you go about getting it?
At the mean time, any danger in continuing to drive this car? Can this problem be ignored totally?

Thanks


----------



## floydarogers (Oct 11, 2010)

rhdmd said:


> I have a 2009 335D, 45700mi. Never have any problem. Regular warranty is out. The SES light came on twice and went off, then it came on a third time and stayed on. Took it into the dealer and they said that the first two SES light was from a Mass Airflow sensor fault and the third is from the SCR active tank sensor assembly. It sounds very much like the problems you all are talking about. These are clearly part of the emission system. It should be covered under the California 7 year/70000 miles emission warranty. But they told me they checked the list of parts under the warranty and did not find them on the list so it is not covered by the warranty.
> Someone on the forum has said that the dealers do not know anything about the emission warranty for the diesel cars because there are so few of them and we should deal with the BMW NA. I tried to talk to the customer relations agent and she said that I need to talk to the dealer. They seem to push the responsibility to each other. What should I do? Anybody here had any success getting this covered by the emissions warranty? Here did you go about getting it?


The dealer has to call BMWNA to check to see if it's covered. However, I (and a couple other owners) have had success in getting the dealer/BMWNA to fix problems with emissions. Show them the warranty in the service and warranty booklet.


----------



## rhdmd (Dec 24, 2013)

Thanks, Floydarogers. On my 2009 335D warranty book, the SCR tank is not listed while it was clearly listed as a warranted item in the list for 2010 and later models. my dealer went strictly with the list and said since it is not o the list, they will not cover it. As the 2010 and later models clearly cover it, it is obviously a well known problem. I intend to appeal the BMW NA. Do any of you know how I can get past the customer relations agent and get to talk to someone who has authority for decisions? 
By the way, my research on the internet seems to suggest that the DEF is only good for 6-24 months depending on the temperature. And deteriorated DEF can render the sensor to produce faulty warning. BMW new policy of just topping off will cause old deteriorated fluid to be left in the tank and compromise the new fluid. So I would not be surprised the SES is partially caused by this. Also the crystallization of the DEF might also cloud the sensor. 
I tried to add more DEF today and found I had to add close to two gallons. Yet the 999 mile warning never came on while in the past, it came on when I was one gallon short. I am thinking that perhaps if I set a regular refill schedule on the DEF, I might be able to ignore this SES and continue to drive it. Do you think that's possible? I was told that this faulty sensor will not affect the performance of the engine but only the emissions if the DEF is too low. It might be critical if we need to do the smog. But being a diesel engine, do we need to do the smog test for the registration renewal in CA.?

The dealer also told me that the first two SES warning was not due to the SCR tank problem but the MassAirflow Sensor. But since it turned itself off relating to that problem, there is no need to replace it yet. If the system detect a fault in that sensor for the third time, it will stay on and that's when it needs to be replaced. Is the mass airflow sensor part of the emissions system also?


----------



## floydarogers (Oct 11, 2010)

rhdmd said:


> .... On my 2009 335D warranty book, the SCR tank is not listed while it was clearly listed as a warranted item in the list for 2010 and later models. my dealer went strictly with the list and said since it is not o the list, they will not cover it. As the 2010 and later models clearly cover it, it is obviously a well known problem. I intend to appeal the BMW NA.


The dealership is supposed to call BMWNA to see if it's covered or not - evidently the list was too long and complicated and they moved the warranty ok to BMWNA. Insist that the SA or service manager call BMWNA. I have no idea who to call in NJ. However, you can call CARB and ask them what to do, they should help you.


----------



## rhdmd (Dec 24, 2013)

floydarogers , Who is CARB? How do I reach them?


----------



## floydarogers (Oct 11, 2010)

rhdmd said:


> floydarogers , Who is CARB? How do I reach them?


California Air Resources Board. They're your regulatory agency for emissions.


----------



## rhdmd (Dec 24, 2013)

EUREKA!!!

I was suspecting the Active tank sensor fault code might be due to the sensor being clouded by the Urea crystal. So after the dealer told me that the replacement of the Active tank is not covered by my 2009 335D California 7 year/ 70000miles Emissions Warranty and I will have to pay $2000 to replace it. I decided to take up the matter with BMW NA. At the mean time, I thought I should try to fill up my DEF tank and see if the new DEF can dissolve the crystal and make a difference. I did so yesterday, after filling up the tank with 2 gallons of DEF until it cannot accept more, the SES light turned itself off today!
I'll see if this will hold up. If so, I think all the DEF tank replacement might have been unnecessary and the BMW NA better revise its policy of topping off and advise owners to refill and keep the tank full at much close interval. Before the 999 miles light comes on., GLTA.


----------



## rmorin49 (Jan 7, 2007)

rhdmd said:


> EUREKA!!!
> 
> I was suspecting the Active tank sensor fault code might be due to the sensor being clouded by the Urea crystal. So after the dealer told me that the replacement of the Active tank is not covered by my 2009 335D California 7 year/ 70000miles Emissions Warranty and I will have to pay $2000 to replace it. I decided to take up the matter with BMW NA. At the mean time, I thought I should try to fill up my DEF tank and see if the new DEF can dissolve the crystal and make a difference. I did so yesterday, after filling up the tank with 2 gallons of DEF until it cannot accept more, the SES light turned itself off today!
> I'll see if this will hold up. If so, I think all the DEF tank replacement might have been unnecessary and the BMW NA better revise its policy of topping off and advise owners to refill and keep the tank full at much close interval. Before the 999 miles light comes on., GLTA.


Congrats on the DIY fix. You might consider purchasing your DEF at a local truck stop. They sell the stuff by the gallon at a pump just like diesel fuel. In my area, it sells for less than $3/gallon. I would think they would go through the stuff pretty fast so it ought to be fresh. Just a thought. Happy Holidays!


----------



## montr (Oct 7, 2006)

rhdmd said:


> EUREKA!!!
> 
> I was suspecting the Active tank sensor fault code might be due to the sensor being clouded by the Urea crystal. So after the dealer told me that the replacement of the Active tank is not covered by my 2009 335D California 7 year/ 70000miles Emissions Warranty and I will have to pay $2000 to replace it. I decided to take up the matter with BMW NA. At the mean time, I thought I should try to fill up my DEF tank and see if the new DEF can dissolve the crystal and make a difference. I did so yesterday, after filling up the tank with 2 gallons of DEF until it cannot accept more, the SES light turned itself off today!
> I'll see if this will hold up. If so, I think all the DEF tank replacement might have been unnecessary and the BMW NA better revise its policy of topping off and advise owners to refill and keep the tank full at much close interval. Before the 999 miles light comes on., GLTA.


We all know, the dealers do not fix thing. They only replace parts.


----------



## Hivolts (Nov 4, 2013)

*DEF Refill*



rhdmd said:


> EUREKA!!!
> ... If so, I think all the DEF tank replacement might have been unnecessary and the BMW NA better revise its policy of topping off and advise owners to refill and keep the tank full at much close interval. Before the 999 miles light comes on., GLTA.


So by "topping off", you are saying they add DEF before its due? So it's best to wait until its close to empty but prior to the 999 mile light? I didn't get an extended warranty so I need to figure out what keeps this thing out of the shop!!


----------



## rhdmd (Dec 24, 2013)

From my research, I found out that the DEF rate of usage is about 2% of diesel. So for every 100 gallons of diesel used, we use up 2 gallons of the DEF. Use this formula and plan your refill schedule. I would not go with the dealer or BMW suggested DEF schedule.
Unfortunately, this discovery is too late for me now. The damage had been done.
Now I realize there is a passive tank and an active tank. The passive tank is just a simple reservoir that holds about 5 gallons of DEF. It feeds into the Active tank which holds only about 1.5 gallons.. i think the sensor in the active tank controls the refilling of the active tank from the passive reservoir. In my case, two things might have happened. When they did the top off, the dealer only topped off the active tank. The reason for this suspicion is as follows:
When I first got the car, I went through three months of driving with no 999 warning light. But after the first service, the warning light came on after 6000 mi of driving. I refilled it (only the active tank as I realized now) and it went on for another 6000 approximately when the 999 light came on again. I filled it again and drove some more and then I had the service. Since then, I had not had a service. I think what happened is the passive tank never got topped off. So I had been operating on the active tank reserve. The sensor might have been damaged by "burnt-out" or clouded because it has been exposed to crystal resulted from drying. When i filled up the active tank and top it off, it dissolved the crystal or the computer detected that the active tank is filled and interpreted as the sensor working properly and did its job. I have not topped off the passive tank yet. I would not be surprised if I try to drain it, I would find it empty. You should try filling both the active and the passive tank. Fill up the active tank first by using the lower inlet and then fill the upper and see how many gallons it takes. i bet it will take about 5.

As for my 335D, this episode has been a very bad experience with both the dealer and the BMW NA. The CA Emissions regulation stipulates that the car should have a 7 years/ 70000 miles warranty on the emissions system. And yet when I had the SES and found out it was the Active tank sensor fault, the dealer refused to replace the tank on warranty saying that it is not on the warranty list for the 2009 model. Yet I found the tank is clearly on the list of warranted items on 2010 and after models, which i take clearly means it is part of the emissions system. But since 2009 is the first year they sold the car, the list of warranted items might not have been complete due to lack of experience. I raised these points to the dealer and the BMW. But they both point the fingers to each other and said it is the responsibility of the other party to determine whether it should be covered. At the end, both said since it is not on the list, they don't want to cover it. I was so pissed at BMW that I immediately sold it after the SES went off. I love this car. It is especially evident when i searched for the replacement car. Test drive after test drive, there just isn't anything out there that is as much fun to drive. Since they have stopped making the 335D and only produce the 325D, I think this is the last great car we can get. I definitely have regret getting rid of it. But yet I had to do it by principle and I really do not want to risk other problems rearing their ugly heads and have to fight with these dishonorable scums again. Just too bad, BMW makes great car, but have lousy ethics.

If I had to do it over again, I would definitely buy the extended warranty so i can enjoy the car longer. But it is still an issue once the warrant runs out. With the computerized system, it makes it hard for independent mechanics to work on it and also getting the parts is a big problem. If you search the Internet, there are quite a few issues with this car that can end up with a big repair bill. Too many sensors and computer-regulated functions. And you know about European electronics. To me, a little too much risks for me to handle. Good luck.


----------



## 335dFan (Nov 8, 2012)

rhdmd said:


> From my research, I found out that the DEF rate of usage is about 2% of diesel. So for every 100 gallons of diesel used, we use up 2 gallons of the DEF. Use this formula and plan your refill schedule. I would not go with the dealer or BMW suggested DEF schedule.
> Unfortunately, this discovery is too late for me now. The damage had been done.
> Now I realize there is a passive tank and an active tank. The passive tank is just a simple reservoir that holds about 5 gallons of DEF. It feeds into the Active tank which holds only about 1.5 gallons.. i think the sensor in the active tank controls the refilling of the active tank from the passive reservoir. In my case, two things might have happened. When they did the top off, the dealer only topped off the active tank. The reason for this suspicion is as follows:
> When I first got the car, I went through three months of driving with no 999 warning light. But after the first service, the warning light came on after 6000 mi of driving. I refilled it (only the active tank as I realized now) and it went on for another 6000 approximately when the 999 light came on again. I filled it again and drove some more and then I had the service. Since then, I had not had a service. I think what happened is the passive tank never got topped off. So I had been operating on the active tank reserve. The sensor might have been damaged by "burnt-out" or clouded because it has been exposed to crystal resulted from drying. When i filled up the active tank and top it off, it dissolved the crystal or the computer detected that the active tank is filled and interpreted as the sensor working properly and did its job. I have not topped off the passive tank yet. I would not be surprised if I try to drain it, I would find it empty. You should try filling both the active and the passive tank. Fill up the active tank first by using the lower inlet and then fill the upper and see how many gallons it takes. i bet it will take about 5.
> ...


Passive reservoir is 14.4 liters (3.8 gals); active reservoir is 7.4 liters (1.95 gals).


----------



## Flyingman (Sep 13, 2009)

I'm pretty sure the vast majority of us have not had any issue with just refilling the def at the scheduled oil change interval of 13,000 miles, +-.

The only time I had an issue was shortly after a service when they supposedly reflled the DEF but did not. I returned, they filled it and apologized. I have 65k now and haven't paid extra for DEF.

If folks are having issues it really should be a dealer problem. They are either not filling it properly or there is something wrong with the DEF system, which many of us have had problems with sensors, heater, transfer pump, etc...

The extended warranty I certainly feel is a must do if you are going to keep this car beyond the 4 year/50k mile point. It's the price we pay to have a "green" vehicle.


----------



## touareg$$$ (Apr 2, 2014)

*Urea Tank Issues*

I'm new to the forum and I would like to join the complaints concerning the urea injection system. I have a 2009 335D with 55000 miles on it and 9 months out of warantee. I've been hit with the level sensor fault back in November (2 months out of warantee). I took the car to the dealer. They topped off the tank and reset the code. 6 months later the fault came back. I've read many complaint by owners concerning the sensor. I filed a complaint with BMW NA and was told they cannot help me. I asked for complaint to be elevated. I explained that as a 37 year experienced aerospace engineer the design reliability of the sensor is unacceptable. This situation will impact my desire to purchase another diesel and another BMW. This is my third diesel car and the other two are VWs. They have been trouble free so far.

Everybody who has had a problem should complaint to BMW NA, Consumers Report and any magazine that gives a favorable review of BMW diesel. Every potential buyer that is turned away from BMW diesel will cost BMW more than it would cost BMW to fix the problem and our cars.:thumbdwn:


----------



## F32Fleet (Jul 14, 2010)

touareg$$$ said:


> I'm new to the forum and I would like to join the complaints concerning the urea injection system. I have a 2009 335D with 55000 miles on it and 9 months out of warantee. I've been hit with the level sensor fault back in November (2 months out of warantee). I took the car to the dealer. They topped off the tank and reset the code. 6 months later the fault came back. I've read many complaint by owners concerning the sensor. I filed a complaint with BMW NA and was told they cannot help me. I asked for complaint to be elevated. I explained that as a 37 year experienced aerospace engineer the design reliability of the sensor is unacceptable. This situation will impact my desire to purchase another diesel and another BMW. This is my third diesel car and the other two are VWs. They have been trouble free so far.
> 
> Everybody who has had a problem should complaint to BMW NA, Consumers Report and any magazine that gives a favorable review of BMW diesel. Every potential buyer that is turned away from BMW diesel will cost BMW more than it would cost BMW to fix the problem and our cars.:thumbdwn:


I wonder of the problem is due to the inability to rinse out the tank with distilled water


----------



## touareg$$$ (Apr 2, 2014)

*Mercedes Washes Out the Tank*

I recall a youtube showing the Mercedes tech flushing out the old urea. Urea has a lifelimit so how old is the stuff in your tank? I have on record showing that the BMW tech flushed the system. I think it is on BMW to fix there refill procedure. I feel they didn't work the design out and are using us as an experiment.


----------



## montr (Oct 7, 2006)

touareg$$$ said:


> I recall a youtube showing the Mercedes tech flushing out the old urea. Urea has a lifelimit so how old is the stuff in your tank? I have on record showing that the BMW tech flushed the system. I think it is on BMW to fix there refill procedure. I feel they didn't work the design out and are using us as an experiment.


Initially, at every oil service, the procedure was to extract old DEF prior refilling. In 2012 (if I remember correctly), procedure was changed to just refill, no extraction. See attachment for old procedure.

Now, out of warranty, I just buy 2.5 gallons of DEF and refill when I get the DEF low message. I do not try to top it off. This way, I fill it about twice as often but I always have fresher DEF.


----------



## Flyingman (Sep 13, 2009)

Think "extended warranty"! There's been plenty of warning about this.:eeps:

I realize it may not be something you want to hear or are willing to pay for, but it's offered for a reason. Peace of mind.:thumbup:


----------



## touareg$$$ (Apr 2, 2014)

*Flash Your Unit*

I went to a European car specialist and he said there is a new computer update that solves the DEF Level Sensor fault. If the dealer is telling you to replace the tank without first falshing the computer, run away. He is out to rip you off! :yikes:

Ask the dealer to update your computer memory at your next service or go to someone you can trust.:thumbup:

BMW NA must be dumber than dirt. They should have told this!!!

I hope this helps everyone out.


----------



## montr (Oct 7, 2006)

Flyingman said:


> Think "extended warranty"! There's been plenty of warning about this.:eeps:
> 
> I realize it may not be something you want to hear or are willing to pay for, but it's offered for a reason. Peace of mind.:thumbup:


Luckily, I bought an extended warranty. I should have said "out of free maintenance" instead of "out of warranty".


----------



## Flyingman (Sep 13, 2009)

montr said:


> Luckily, I bought an extended warranty. I should have said "out of free maintenance" instead of "out of warranty".


My response was intended for Touareg$$


----------



## touareg$$$ (Apr 2, 2014)

*SES Light P203A DEF Active Tank Recall*

I just learned that BMW is recalling the diesel car to replace the Active Tank. The service instructions and parts are not available yet. Gather up your repair bills so you can file a claim and recover you expenses.

BMW NA didn't know this last week. Expert service? It is a waste of time talking to them. They are as bad as VWs people. What are we paying for?


----------



## GreekboyD (Jan 25, 2012)

touareg$$$ said:


> I just learned that BMW is recalling the diesel car to replace the Active Tank. The service instructions and parts are not available yet. Gather up your repair bills so you can file a claim and recover you expenses.
> 
> BMW NA didn't know this last week. Expert service? It is a waste of time talking to them. They are as bad as VWs people. What are we paying for?


Interesting. Very interesting.

My passive tank has been clogged for well over a year.


----------



## quasimodem (Nov 9, 2011)

stickyplus said:


> If you live around the Bay area and need to buy parts, especially the oil and DEF, the Fremont BMW dealer is a good choice. They sell these at fair market price, highly recommand it.
> 
> Good luck.


Excellent, I need some oil.


----------



## tonyspumoni (May 23, 2010)

touareg$$$ said:


> I just learned that BMW is recalling the diesel car to replace the Active Tank. The service instructions and parts are not available yet. Gather up your repair bills so you can file a claim and recover you expenses.
> 
> BMW NA didn't know this last week. Expert service? It is a waste of time talking to them. They are as bad as VWs people. What are we paying for?


Is there a campaign code out for this yet?

Sent from BimmerApp mobile app


----------



## quasimodem (Nov 9, 2011)

stickyplus said:


> It seems like the code are related to the lack of the DEF and I called BMW dealer in Fremont and got a 2.5 gallon DEF for $26.00 + tax. The Tank took about half of the container and I put the rest in to the passive tank on the right of the engine.
> 
> If you live around the Bay area and need to buy parts, especially the oil and DEF, the Fremont BMW dealer is a good choice. They sell these at fair market price, highly recommand it.
> 
> Good luck.


Just a FYI, I will stop by Fremont BMW tomorrow to see what they charge for LL-04 oil. Normally I get it at BMW of Mountain View. I am not sure what BMW of MTV is charging now, but I have a receipt for January 2013 and they charged $8.95 per quart and $22.39 for the filter. I got ripped off once on a weekend at Stevens Creek BMW for around $20 a quart once and have never been back there. By the way, I pick up 2.5 gallons of DEF at VW Steven Creek for $12.00, so that $26.00 at BMW of Fremont doesnt sound so good.

Edit: I stopped by BMW of Fremont and their oil price was good -- $8.28 per quart, so I picked up seven quarts and a filter.


----------



## 9mmkungfu (Sep 11, 2014)

touareg$$$ said:


> I just learned that BMW is recalling the diesel car to replace the Active Tank. The service instructions and parts are not available yet. Gather up your repair bills so you can file a claim and recover you expenses.
> 
> BMW NA didn't know this last week. Expert service? It is a waste of time talking to them. They are as bad as VWs people. What are we paying for?





tonyspumoni said:


> Is there a campaign code out for this yet?
> 
> Sent from BimmerApp mobile app


Just wondering if anyone was ever able to get a campaign code for this recall.


----------



## Armand (Dec 20, 2009)

I too would appreciate the campaign code if one exists. Just hit P203A mod $00 code on my 2010 X535d, 53k miles. I have extended warranty so it's tempting to just Take it to the dealer.it has been almost a year since I topped off the def. I might try adding def and see what happens.


----------



## touareg$$$ (Apr 2, 2014)

*P203a*

The only way my "check engine" would reset with a P203a fault was when the ambient temperature rose above 60 degF. You can add fluid but I never had it reset the code. There are temp and permanent codes. Only the dealer or a specialist can remove the code. I was never given the campain number. Contact your dealer. You might as well get your car checked for an "engine miss" code. The diesel is prone to intake carbon build up which will require walnut blasting.


----------



## Armand (Dec 20, 2009)

touareg$$$ said:


> The only way my "check engine" would reset with a P203a fault was when the ambient temperature rose above 60 degF. You can add fluid but I never had it reset the code. There are temp and permanent codes. Only the dealer or a specialist can remove the code. I was never given the campain number. Contact your dealer. You might as well get your car checked for an "engine miss" code. The diesel is prone to intake carbon build up which will require walnut blasting.


I deleted the code with a typical OBD reader. CEL went off. I've topped off the tanks. Passive tank took about 3 gallons. Active tank took about a quart. Have been driving the car since and cell is off for now. Will hold off from going to the dealer until the code is more persistent.


----------



## touareg$$$ (Apr 2, 2014)

*You are lucky*

I had it reset once by the specialist and a DEF refill. It came back when it got cold. Went out when it got warm. I had the tank replaced, walnut blasted the intakes and sold the car.


----------



## kjelly (Sep 29, 2013)

*P203A also*

Received a SES light again, P203A.

I had an oil change and DEF refill done a few months ago by the dealer.

Should I go back and have them add more DEF since it looks like it fixes the problem? I'm in Alabama, so ambient temperature is well above 60F.


----------



## touareg$$$ (Apr 2, 2014)

*Get it fixed*

I would go back to the dealer and get it fixed. The alternative is to ignore the light. I got it fixed for nothing by BMW. If you have an extended warrantee I wouldn't wait. It will not fix itself.

Get ready for the walnut blasting of your intakes.


----------



## diesel fan123 (Nov 25, 2011)

Hi,
After years of driving with the SES on, it appears that BMW found a fix for the "Fuel injector #4" software complaint my car has had!

I had just resigned myself to driving w/ the SES on, as the car performed perfectly, just w/ the annoying SES.
P203A code was just a phantom, nothing actually wrong w/ #4.

Some time ago, I licensed BMWhat software for my Android so I could query the BMW diagnostics and find out if other trouble codes were also activating SES.

In April, car started running poorly, queried diagnostics and found "OO4D16 DENOX SYSTEM EFFICIENCY LOW".
So I took the car in and they replaced the Cat Con, and also put some new software in the DDE. (This is the 3rd or 4th DDE code upgrade so far, also at least one DDE replacement has been done)

After almost two months of driving, 2k miles, no SES!! 
Usually the SES would come on 3-4 days after clearing the diagnostics, so this is great.

This is my first BMW. I knew it was a complicated system when I bought the car, and am impressed that after all these years, BMW apparently devised a solution for the recurring problem.

Frank


----------



## kjelly (Sep 29, 2013)

diesel fan123 said:


> Hi,
> After years of driving with the SES on, it appears that BMW found a fix for the "Fuel injector #4" software complaint my car has had!
> 
> I had just resigned myself to driving w/ the SES on, as the car performed perfectly, just w/ the annoying SES.
> ...


Frank, thank you for the info.

I took my car into the dealer yesterday. They confirmed the code P203A, and said the fix was to replace the SCR tank. The total estimate was approx. $2400.

The service advisor or tech never mentioned anything about a DDE software update. Does your receipt show what software version was installed?

Thanks,
Ken


----------



## montr (Oct 7, 2006)

kjelly said:


> Frank, thank you for the info.
> 
> I took my car into the dealer yesterday. They confirmed the code P203A, and said the fix was to replace the SCR tank. The total estimate was approx. $2400.
> 
> ...


The DDE software update above is for code 4592 the smoothness on injector 4. The OBD code P203A is for the sensor in the DEF tank. Apparently, the sensor cannot be replaced by itself. Instead they replace the tank.

I hope that you do not have to pay $2400. This is a common failure in the 335D.


----------



## kjelly (Sep 29, 2013)

Ok, damn. The service advisor told me the same thing--tank needs to be replaced. I might as well as get the EGR delete


----------



## Armand (Dec 20, 2009)

Armand said:


> I deleted the code with a typical OBD reader. CEL went off. I've topped off the tanks. Passive tank took about 3 gallons. Active tank took about a quart. Have been driving the car since and cell is off for now. Will hold off from going to the dealer until the code is more persistent.


Finally took the car in even though CEL turned off after the last episode. Been having a cat and mouse game with P203A for months now. Long story short, dealer is covering it under CA emissions warranty 7 years/70K miles. As others have stated, the issue is a malfunctioning DEF Active tank sensor. It's on back order and I am supposed to check back in a week. Work order attached.


----------



## Doug Huffman (Apr 25, 2015)

Other posts suggest that DEF tanks are again available, but with considerable backlogged demand.


----------



## tonyspumoni (May 23, 2010)

I parked next to a guy driving a 2010 335d the other day. I once owned a 2010 335d and a 2011 335d M sport and so I asked him if he'd had any trouble with it. "Nope," he said. Makes me wonder what I did wrong with mine to get emissions code after emissions code, plus a DEF tank and sensor. I have not kept track of these diesel threads since I ditched mine but has a theme emerged as to what might be the common fail point, other than stochastic noise?


----------



## Doug Huffman (Apr 25, 2015)

It's just noise. Of many BMW's in the US, a few post here or there complaining. The only way to make a proper estimate would be to detect the happy ones too.

Like my VW, it was as reliable as a brick, but the forums were/are full of problems. I will be glad and relieved when I have the confidence in my X5 that I did in the TDI.


----------

