CEL came on, code P203a. Active tank replaced. **77k mile update, Passive Tank bad!

[scollins]

Figured it was time for an update.

Friday 7/25: SA calls, but I'm in my truck driving, so I have the wife take the call. She says "OK" about a million times (typical phone conversation for her it seems) and finally says "OK, we can't pick it up until Monday anyway because we are out of town." I'm thinking, "What?"

She hangs up and says the fuel filter heater has been replaced, and they are doing a "complete software update, free of charge." That sounds suspicious to me, as I doubt replacing this heater filter requires an update. Whatever, it isn't costing me anything, so what the hell. I'm actually thinking they are trying to erase the permanently stored fault codes to cover their tracks.

Saturday 7/26: SA calls again with impeccable timing, as I'm again driving and tell the wife to take it. The story now is that the area where the dealer is located lost power, so the update was interrupted. They don't know when power will be back, but they'll have to start the update over again afterwards. Likely be Monday late morning/afternoon before the car is ready. Wife says "OK, but if it goes past noon, we'll need a loaner car." Not an issue. So what the hell, these things happen. Or do they?

Sunday 7/27: Back home from our camping trip, and I'm talking with my neighbor. His office happens to be right next to the BMW dealer, and he was at work all day on Saturday and knows nothing about a power outage. It is possible, as I've had power when my neighbor across the street didn't, so not totally implausible. But with everything else, seems quite fishy......

Monday 7/28: SA calls, and this time I can take the call. Apparently now there is a fried FRM module that needs to be replaced. "So that power outage fried the FRM Module, right?" SA says "No, it was likely faulty before. But I've got the OK for the same 80/20 deal." I say that is likely bullshit, you fried the FRM and are trying to get me to cover part of the cost. But I have no proof, and they aren't budging on it, so I say "how much?" $60. Fuck it, just fix my fucking car and be done with it! And I'm probably done with BMW Bellevue too, but I don't say that.

I'm now looking at $200 out of pocket, which in the scheme of things isn't bad considering I don't have warranty coverage. This in theory gets me the latest fuel filter heater, so not likely to be defective as previous models have been, and a new FRM module, that I likely didn't need, nor should have paid for it. But again, they are wearing me down and the fight isn't worth my time at this point.

Tuesday 7/29: I call at 3:50 PM wondering what the status is of my X5. The SA says "we just finished the paperwork, you can come pick it up." Great! Finally! In the shop 7 days for a CEL.

I go to the cashier, and read every word on the invoice before handing over my CC for the $200. The first part says:
B** "Customer states SES light on, please check.
Performing Vehicle test
1125 WB
8703 WB
1 13-32-8-575-515 Fuel strainer with heating: 133010
1 07-12-9-952-104 Hose clamp: 079510
1332551 Replacing fuel filter
1125 WB
FC: 13320012SA

65635 Fuel Filter heater (1-2, 4, 8703) interrogated fault memory and found fuel filter heating faults ran test plan and per diag code: D1330_D000000_07_001 found the fuel filter heating internally faulty. parts ordered at this time. (3 1125) removed and replaced diesel fuel filter with fuel filter heater (5 1125) cleared fault memory and road tested. fault was no longer present.

E** Failure to FRM module
Cause
6100009 SIB 65 27 08 (My notes: This SIB talks about FRM failure, but only covered under Manuf. warranty period, which I'm out of. But again, a known problem.....)

1125 WB
1 61-35-9-308-375 footwell module 3: 613020
6100710 Program without CAS
1125 WB
6100980 QUICK DELETE WITH PROG
1125 WB
6100711 PROGRAM 1ST ABORT
1125 WB
6135616 REPLACING FOOTWELL MODULE
1125 WB
6100712 PROGRAM W/O CAS
1125 WB
FC: 61380615SA

65636 FRM SHORTED INTERNALLY 2.00 (1) INSPECTED AND VERIFIED THAT THE LIGHT MALFUNCTION WARNING WAS ACTIVE. RAN A SHORT TEST TO CHECK FOR UNRESPONSIVE. (2) CHECKED SUPPLY VOLTAGE AND GROUND TO FRM MODULE, NO FAULTS WERE FOUND (3) CODED AND PROGRAMMED VEHICLE TO RESCUE FRM, PROGRAMMING FAILED. (4) PERFORMED BATTERY RESET AND ATTEMPTED TO PROGRAMMING AGAIN, PROGRAMMING FAILED. (5) REMOVED AND REPLACED FRM. (6) CODED AND PROGRAMMED TO VEHICLE. CLEARED FAULT MEMORY AND ROAD TESTED. FAULT WAS NO LONGER PRESENT."


So sections B & E deal with the fuel filter heater and the FRM module. Ok, everything should be fine now. When I walked in my SA was on the phone, so I didn't bother to stop and talk to her. Probably wasn't worth the time anyway. I walk out to the waiting area and a few minutes later my X5 pulls up. I do a quick walk around and get in the running X5. WHAT IN THE BLUE FUCK IS THAT ON THE DASH!!!!! THE GOD DAMN YELLOW CEL IS STILL ON!!!!!!!!!

I literally drive the X5 20 feet right back into the service drop off lane and go find my SA. She has to be paged, and she shows up. I say "Why is the CEL still on? That's the whole reason I brought it in." She has a look on her face like "oh shit......" She apologizes, and says she'll get with the Service Manager right away and figure out what is going on. Since it is already 4:30 PM, I know they won't get to it today. I get back the same loaner car I had (325d) and leave the dealership.

The good thing here is that the CEL was already back on before I left the dealership, not 5 miles down the road. I had meant to bring my OBD reader, but forgot it at home. But I'm certain the P203A code was back.

I'll be waiting tomorrow (day 8 in the shop) to see what they come up with this time......




So, thoughts on:
Volvo XC90
Audi Q7
Porsche Cayenne
(The wife still wants an SUV, although I'm pushing for a sedan or wagon......)
Oh, and it will be leased for a period shorter than the warranty period.

[bawareca]

Any shop could be heartbreaking,hopefully you take it not too deep.Everytime
I let a shop to do fomething on any of my cars I want to bang my head in the wall.There are exceptions,but yours was not.

Originally Posted by scollins

So, thoughts on:
Volvo XC90
Audi Q7
Porsche Cayenne

That will make you come back to BMW very quickly Porsche and Audi can only dream of BMW-like reliability,and that is not a joke.More interesting question is what brand is Volvo now:Swedish,Chinese,Indian or Malaysian?Who develops their electronics?Who develops their engines,trannys,etc?Where is the Volvo dealer?
Trying to fix the hangover with more rum tequila may lead to a result different than expected

[ard]

Coulda sworn I said it wasnt a fuel filter heater.

Thanks for the update. We feel your pain. Just imagine how you'd feel if you were paying 100%.

Oh, I didnt recognize a single fault code...not a one. part numbers an work codes.

Fault codes are 4 digits, 4DA2 or 2308, etc

I wonder what would happen if you refused to OK the 20% on the FRM that failed when they were programming it? Not that they caused it, but it failed during software load- would they insist you come tow the car away??? Just wondering..

Oh, if it does get fixed, insist they pull it around BEFORE you sign anything- sit in it idling and revving for 10 minutes and THEN go sign. and dont return the loaner either.

GL...

PS Dont let the wife take those calls. SAs interpret this as a lcense to do almost anything they want.

PPS did you call them out on the power outage lie?

[scollins]

My SA continues to have impeccable timing with calls. This time I was on a conference call, so, I just let it go to voicemail. SA says the problem has been identified as the active DEF tank, and it will be fixed and ready tomorrow. She also said it was submitted to BMWNA as a "goodwill" repair, which it is not. It falls under the CA emission warranty and is a specifically listed part. I don't care what they call it, this is one repair I am absolutely NOT paying a penny for. Of course, I got her voicemail when I called back.

But I do feel some vindication in knowing I was right from the start. I did resist the urge to say "I told you so" on the voicemail.

[ard]

You really ought to have a conversation with the service MANAGER and the actual Technician that worked on the car. A little polite shaming is called for... IMO

Explain that you knew it was a DEF issue, yet because of either BMWs flawed software tools, or improper diagnosis by the dealer, you (and BMW) paid for a fuel filter heater. Then, again due to flawed software or someone screwing up the programing you paid for another module....and returned the car with a CEL!!

Only after X days and Y dollars did someone finally address the DEF code you reported a week ago.

"Look, I understand these are not simple cars, and diagnostics can be compex- but this is clearly a case where flawed diagnostic work has cost me $xxxx. This is simply unacceptable."

See what they say.

(They never gave you the very first code that coincided with your OBD P-code...curious...)

Also, these DEF errors come with SCR issues and such...so you may not be out of the woods entirely. Great news is that you have a record of multiple failures when it is still under warranty...

Good luck

[scollins]

Picked up the X5 today, and thankfully there was no CEL/SES on the dash this time. Here are the comments on the work order:
65647 ACTIVE TANK SENSORS SHORTED INTERNALLY (1) INSPECTED AND VERIFIED THAT THE SES LIGHT WAS ON. (No fucking shit, really?? Did you think I was making it up?) RAN A SHORT TEST TO CHECK FOR FAULTS IN THE CONTROL MODULES. FOUND FAULTS PRESENT IN THE DDE FOR ACTIVE TANK MONITORING ERROR. (2) RAN TEST PLAN FOR ACTIVE TANK AND FOUND THAT THE TANK SENSORS WERE SHORTED INTERNALLY AND REQUIRED REPLACEMENT PER DIAG CODE: D1170 00000000 30 001. (3-5) REMOVED AND REPLACED ACTIVE TANK. (6) TOPPED OFF SCR FLUID. (7) CLEARED FAULT MEMORY. (8) ROAD TESTED AND RECHECKED, FAULT NO LONGER PRESENT


My SA wasn't there today, but the Service Manager was. I asked to speak to him to give him some direct feedback on the whole process. Both my wife and I were in this meeting that lasted about 20 minutes. The net result is that my opinion of BMW Bellevue 's service department is even lower. Says something when the guy in charge of service doesn't even drive a BMW (his own words). My wife's impression of the guy was that he was a complete idiot (her words.) I expressed my concern over trying to deliver a vehicle back to the customer with the CEL/SES still on, and given that a scan of a different module found the errors in the active tank, why weren't they caught before? No real good answer came from the SM. I then asked why if I can read an OBDII code, search the internet, and pinpoint at least the subsystem with the issue why they couldn't do the same? His response was "we ignore what the customer says, as well as OBDII codes. BMW has their own test plans and systems, so that is what we use."

O-M-G! Did you really say you "ignore what the customer says"? Wow, just wow. Hell, at least sugar-coat it and make it sound less patronizing, like "we appreciate the input from our customers and we do our best to implement BMW's test plans and protocols to the highest standards."

I then asked why the error wasn't caught earlier if the technicians followed the protocols in the testing plans, and why the X5 still had the CEL/SES on when I tried to get it earlier. His response can be summed up with:

And he kept asking why we didn't buy the extended warranty, because BMW is less likely to help out customers with "goodwill" repairs if they didn't buy the extended "warranty". What, that doesn't make any sense. Had I bought the extended warranty, they would have just covered everything after the deductible, where would "goodwill" factor into that?

I also said that if BMW can't build a car that can go at least 100,000 miles without THOUSANDS of dollars in repairs (not maintenance, but repairs), then I either need to stop buying BMWs or just lease them and turn them in before the factory warranty expires. He agreed with that statement, saying you shouldn't own a BMW outside of warranty, either factory or extended. Again, that doesn't inspire confidence in continuing to buy the brand when the SM says something like that.

And when the extended "warranty" costs $5,000 just to cover an additional 2 years and 50,000 miles of ownership, how much confidence should I have in the product? He didn't have an answer for that, other than to repeat about not owning one outside of warranty. He then shared a story about having to do a $12,000 warranty repair on his previous M5, and how he was glad he had the extended warranty for that.

There was some additional discussion about training opportunities for their Service Advisors, especially with BMW selling more diesel cars than ever in the US. If your SA's can't tell the difference between SCR (a process) and DEF (a reactant used in the SCR process), they might need additional training.

I walked out of the meeting pretty much just shaking my head.

My final concerns are that the passive tank is going to have the same issue shortly, as it appears they didn't even run a test plan on that unit. So I'm hoping for two outcomes: The passive tank is fine and doesn't have an issue, or if it does, it appears in the next 5,000 miles. If it shits the bed after 100,000 miles, I'll be somewhat OK with that (but only somewhat.) By then, "alternate options" will likely exist....

The X5 goes back in for an oil change in about 1,500 miles. We did buy the extended maintenance contract because that penciled out in our favor vs. the local indy shops for comparable service. I think I'll give BMW Seattle a shot on that service and see how they do. Should be an easy test to pass.....

The last thing I'm going to start doing is refilling the DEF tanks every 4th fill-up. Not sure that will help, but it seems that crystallization of the UREA on the sensors may be a contributing factor. Maybe keeping the tanks topped off will reduce or eliminate that issue.

[Quicksilver]

Very interesting conversation.

""We ignore what the customer says" Nice way to say that customers are stupid.
(It's true some are). But some customers know their vehicles.
Either way you don't ignore customers.

"He kept asking why we didn't buy the extended warranty."
Does that mean they would have found the problem in a more
expedient manner. I don't think so and shifting the
blame for incompetence is a clear signal that it's time to find
someone else to repair your vehicle.

To be honest I believe I would write a (Non Emotional) letter
spelling out the facts and while BMWNA won't act if they read it
I would pass it along to them as well. You might get a call from the
dealer to get this matter settled.

I don't believe a customer should be disrespected for any reason.

Originally Posted by scollins

His response was "we ignore what the customer says, as well as OBDII codes. BMW has their own test plans and systems, so that is what we use."

O-M-G! Did you really say you "ignore what the customer says"? Wow, just wow. Hell, at least sugar-coat it and make it sound less patronizing, like "we appreciate the input from our customers and we do our best to implement BMW's test plans and protocols to the highest standards."

I then asked why the error wasn't caught earlier if the technicians followed the protocols in the testing plans, and why the X5 still had the CEL/SES on when I tried to get it earlier. His response can be summed up with:

And he kept asking why we didn't buy the extended warranty, because BMW is less likely to help out customers with "goodwill" repairs if they didn't buy the extended "warranty". What, that doesn't make any sense. Had I bought the extended warranty, they would have just covered everything after the deductible, where would "goodwill" factor into that?

[Hbones11]

Originally Posted by scollins

Picked up the X5 today, and thankfully there was no CEL/SES on the dash this time. Here are the comments on the work order:

65647 ACTIVE TANK SENSORS SHORTED INTERNALLY (1) INSPECTED AND VERIFIED THAT THE SES LIGHT WAS ON. (No fucking shit, really?? Did you think I was making it up?) RAN A SHORT TEST TO CHECK FOR FAULTS IN THE CONTROL MODULES. FOUND FAULTS PRESENT IN THE DDE FOR ACTIVE TANK MONITORING ERROR. (2) RAN TEST PLAN FOR ACTIVE TANK AND FOUND THAT THE TANK SENSORS WERE SHORTED INTERNALLY AND REQUIRED REPLACEMENT PER DIAG CODE: D1170 00000000 30 001. (3-5) REMOVED AND REPLACED ACTIVE TANK. (6) TOPPED OFF SCR FLUID. (7) CLEARED FAULT MEMORY. (8) ROAD TESTED AND RECHECKED, FAULT NO LONGER PRESENT





My SA wasn't there today, but the Service Manager was. I asked to speak to him to give him some direct feedback on the whole process. Both my wife and I were in this meeting that lasted about 20 minutes. The net result is that my opinion of BMW Bellevue 's service department is even lower. Says something when the guy in charge of service doesn't even drive a BMW (his own words). My wife's impression of the guy was that he was a complete idiot (her words.) I expressed my concern over trying to deliver a vehicle back to the customer with the CEL/SES still on, and given that a scan of a different module found the errors in the active tank, why weren't they caught before? No real good answer came from the SM. I then asked why if I can read an OBDII code, search the internet, and pinpoint at least the subsystem with the issue why they couldn't do the same? His response was "we ignore what the customer says, as well as OBDII codes. BMW has their own test plans and systems, so that is what we use."



O-M-G! Did you really say you "ignore what the customer says"? Wow, just wow. Hell, at least sugar-coat it and make it sound less patronizing, like "we appreciate the input from our customers and we do our best to implement BMW's test plans and protocols to the highest standards."



I then asked why the error wasn't caught earlier if the technicians followed the protocols in the testing plans, and why the X5 still had the CEL/SES on when I tried to get it earlier. His response can be summed up with:



And he kept asking why we didn't buy the extended warranty, because BMW is less likely to help out customers with "goodwill" repairs if they didn't buy the extended "warranty". What, that doesn't make any sense. Had I bought the extended warranty, they would have just covered everything after the deductible, where would "goodwill" factor into that?



I also said that if BMW can't build a car that can go at least 100,000 miles without THOUSANDS of dollars in repairs (not maintenance, but repairs), then I either need to stop buying BMWs or just lease them and turn them in before the factory warranty expires. He agreed with that statement, saying you shouldn't own a BMW outside of warranty, either factory or extended. Again, that doesn't inspire confidence in continuing to buy the brand when the SM says something like that.



And when the extended "warranty" costs $5,000 just to cover an additional 2 years and 50,000 miles of ownership, how much confidence should I have in the product? He didn't have an answer for that, other than to repeat about not owning one outside of warranty. He then shared a story about having to do a $12,000 warranty repair on his previous M5, and how he was glad he had the extended warranty for that.



There was some additional discussion about training opportunities for their Service Advisors, especially with BMW selling more diesel cars than ever in the US. If your SA's can't tell the difference between SCR (a process) and DEF (a reactant used in the SCR process), they might need additional training.



I walked out of the meeting pretty much just shaking my head.



My final concerns are that the passive tank is going to have the same issue shortly, as it appears they didn't even run a test plan on that unit. So I'm hoping for two outcomes: The passive tank is fine and doesn't have an issue, or if it does, it appears in the next 5,000 miles. If it shits the bed after 100,000 miles, I'll be somewhat OK with that (but only somewhat.) By then, "alternate options" will likely exist....



The X5 goes back in for an oil change in about 1,500 miles. We did buy the extended maintenance contract because that penciled out in our favor vs. the local indy shops for comparable service. I think I'll give BMW Seattle a shot on that service and see how they do. Should be an easy test to pass.....



The last thing I'm going to start doing is refilling the DEF tanks every 4th fill-up. Not sure that will help, but it seems that crystallization of the UREA on the sensors may be a contributing factor. Maybe keeping the tanks topped off will reduce or eliminate that issue.

Wanted to add my story to the list of P203A/P205B CEL issues and add my thoughts.



Bought my 2010 X5 diesel in August 2013, ~58k miles. Started pulling a P2621 code (Throttle Position Output Circuit Low) around June 2014, ~75k miles. Did some research on the code and kept resetting it while driving around with the code until late August. I live in the DC metro area and finally decided to take the car back my uncle's garage in Northeast PA to get his opinion. He immediately told me to look at the EGR (Exhaust Gas Recirculation) valve.



The EGR valve is tedious to remove but after about an hour or so I was able to remove it only to find something similar to the valve in this YouTube video.



https://www.youtube.com/watch?v=KQx_...ature=youtu.be



That EGR cleaning was done on a different engine (X3 2.0d with a different CEL code) but the valve is pretty much the same as the 3.5d.

I cleaned my valve, reinstalled, and cleared the codes. The car drove for only a few hundred miles until the P2621 code came back.



Decided to take my X5 to another garage in Northeast PA that specializes in European cars. I told tech about the code and the EGR valve cleaning. He said he would run some tests to check if the EGR valve was functioning properly. Come to find out the valve was toast at ~81k miles.



The EGR valve helps your car more efficiently and completely burn fuel by recirculating a portion of your exhaust and running it through the combustion process again. Since my valve was toast, that made sense to me because I started seeing white DEF residue on/around my tailpipes once the P2621 code started showing up (an issue I've read about on multiple diesel blogs).



Drove the car for another few hundred miles, didn't see any white DEF residue, but had the P203A/P205B codes appear (never had them previously). After consulting a few Technical Service Bulletins, reading similar blog posts, and talking to some diesel techs I have the following thoughts:



1. I have a hunch my P203A/P205B codes are due to any white DEF residue that is lingering in the system.

2. Based on the codes, I think my issue is related to sensors in the active DEF tank. My understanding is the passive DEF tank does not contain any sensors and only feeds the active tank when it drops below a certain level.

3. I do not believe the sensors in the active DEF tank are toast. I've read blog posts about flushing the DEF tank with hot or warm soapy water multiple times. Some posts have confirmed this fixed the P203A/P205B codes.

4. I haven't had a chance to flush my active DEF tank, but if that doesn't work I don't think you are able to buy just the active DEF tank sensors. This would obviously result in me replacing the active DEF tank to fix any sensor issues (if I haven't found any other avenues to pursue).



Here is a link to all the parts that make up the active DEF tank assembly:

Scr container active. Fits: 2010 BMW X Series (E53,E70,E71,E83) X5 3.5d | BMW of South Atlanta



Hope this helps anyone that is struggling with similar issues.

[scollins]

Originally Posted by Hbones11

Wanted to add my story to the list of P203A/P205B CEL issues and add my thoughts.

Bought my 2010 X5 diesel in August 2013, ~58k miles. Started pulling a P2621 code (Throttle Position Output Circuit Low) around June 2014, ~75k miles. Did some research on the code and kept resetting it while driving around with the code until late August. I live in the DC metro area and finally decided to take the car back my uncle's garage in Northeast PA to get his opinion. He immediately told me to look at the EGR (Exhaust Gas Recirculation) valve.

The EGR valve is tedious to remove but after about an hour or so I was able to remove it only to find something similar to the valve in this YouTube video.

https://www.youtube.com/watch?v=KQx_...ature=youtu.be

That EGR cleaning was done on a different engine (X3 2.0d with a different CEL code) but the valve is pretty much the same as the 3.5d.
I cleaned my valve, reinstalled, and cleared the codes. The car drove for only a few hundred miles until the P2621 code came back.

My uncle suggested I take my X5 to another garage in Northeast PA that specializes in European cars. I told tech about the code and the EGR valve cleaning. He said he would run some tests to check if the EGR valve was functioning properly. Come to find out the valve was toast at ~81k miles.

The EGR valve helps your car more efficiently and completely burn fuel by recirculating a portion of your exhaust and running it through the combustion process again. Since my valve was toast, that made sense to me because I started seeing white DEF residue on/around my tailpipes once the P2621 code started showing up (an issue I've read about on multiple diesel blogs).

UN-EFFING-BELIEVABLE!! Here is what code my X5 threw on 11/26/14:



After some Googling, I figured the problem was the EGR/throttle valve based on the error code and symptoms (shudder on shutdown.) Ordered the part from GetBMWparts.com for $375 and went about installing it. Part # 11-71-7-804-384, plus the o-ring #13-54-7-792-098.

The old valve looked like this:


While the valve is a fairly exposed position, getting to the three mounting screws was a bitch. I had to use my 1/4" drive socket with the ball-end of the proper sized Allen wrench that I cut to fit. There was a small support bracket that I could not get back on due to misalignment issues with the screws. It was causing enough deflection that the screw would start to cross-thread. Steel screw into aluminum housing with misalignment = bad juju.

That was at 70,500 miles. I called an independent shop for a quote, and they thought it might actually be covered under an extended "secret" warranty. If not, then the part would be $550 and about 1.5 hours to install ($110/hr shop rate.) When I said I could get the part online for $375, they said that was better than their cost because they have to source parts from the dealer. That was $800 out the door.

I called my current go-to dealer, BMW Seattle, and asked about extended warranties on the part. They didn't show anything based on my VIN, so I said "screw it" and did the work myself. I could have likely taken it in and argued that I was just past the 70,000 miles for the CA Emissions Warranty and gotten it covered, but I was tired from the ordeal with DEF tanks.

Honestly, I blame the government and their "emissions" laws. What engineer would honestly CHOOSE to recirculate dirty, nasty exhaust gas back INTO the intake? Or put on a complex Urea injection system to reduce emissions, but hamper reliability in the long term. I expect the diesel block itself to last damn near forever, it's the government mandated shit-systems that are causing the problem.

And since the lift struts went out in October, to the tune of $1,400 at the Indy Shop, I'm really FED UP with this SAV. I'm all set to dump the thing and just start leasing, but for some reason the wife (it's her car after all) seems content currently. The next time the damn CEL comes on, I might just run the thing into a wall at 60 MPH.....

I'm kidding about that, but I personally am shopping lease deals. Hell, I'd even take another X5, but I'm learning my lesson about owning these "high tech" cars out of warranty. Sadly, I don't think that is limited to just BMW. Even my Toyota Tacoma with "legendary" reliability isn't exactly the model it once was.......

[PGas32]

Originally Posted by Hbones11

Drove the car for another few hundred miles, didn't see any white DEF residue, but had the P203A/P205B codes appear (never had them previously). After consulting a few Technical Service Bulletins, reading similar blog posts, and talking to some diesel techs I have the following thoughts:



1. I have a hunch my P203A/P205B codes are due to any white DEF residue that is lingering in the system.

2. Based on the codes, I think my issue is related to sensors in the active DEF tank. My understanding is the passive DEF tank does not contain any sensors and only feeds the active tank when it drops below a certain level.

3. I do not believe the sensors in the active DEF tank are toast. I've read blog posts about flushing the DEF tank with hot or warm soapy water multiple times. Some posts have confirmed this fixed the P203A/P205B codes.

4. I haven't had a chance to flush my active DEF tank, but if that doesn't work I don't think you are able to buy just the active DEF tank sensors. This would obviously result in me replacing the active DEF tank to fix any sensor issues (if I haven't found any other avenues to pursue).

I agree that the 203/205 codes are most likely related to DEF crust on the sensors. I'll have to flush the tanks out at some point. In the meantime, there seems to be no impact to anything aside from the CEL remaining on.