# Wrong DEF Error



## PROEASY (Nov 17, 2015)

Apologies, but could not find a search function on this topic, or any others. 

2014 535D X Drive 
72,000 Miles
fully maintained by myself, oil changes brakes etc
Yesterday go the "Wrong Diesel Fluid Added, no start in 200 miles" now down to 150
can not clear the code with Schwaben Scan tool 
I use only BMW or Peak DEF
I am sure I have to take it to the dealer
Any similar stories and expected costs?

thanks

Paul


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## Doug Huffman (Apr 25, 2015)

Yes, it has happened to many. You will have to take it to the BMW Service Center. 

The wrongness of the DEF is measured indirectly by inadequate response to an injection of presumed good DEF. Often caused by sensor problems, mixer injection nozzle problems.

There may be an Extended Limited Warranty - ELW - in effect for your car that may help.

A good bit of my SCR was replaced under ELW.


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## PROEASY (Nov 17, 2015)

Thanks, I see in my paperwork there is ELW on the following for the Diesel, I suppose the preventative replacement of the DEF Injector may have helped

EGR Cooler
Nox Sensor
EGR Valve
High Pressure Pump

Paul


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## mjez (Jan 16, 2014)

I'm not sure if that would help to extend your "no start" mileage counter or not but has anyone tried disconnecting DEF module in this situation? 

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## HotGrbg (Apr 23, 2021)

It will not extend your no start condition sadly. The only thing that clears the no start is when the DDE successfully runs an SRC system test that passes.


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## HackMech (May 5, 2021)

I have the same car, with the same idiot message. Took it to the dealer. They dropped the SCR Tank and reported bad fluid and nonworking pump. $3500 later a new tank was installed. I drive 35 miles, the check engine comes on again. Back to the dealer, they reported to have regen the car three times and no faults. I drive 35 mile and same skit with the check engine light. Back to the dealer a third time. They proceed to change the two Nox sensors under the 10yr/120 mile extended warranty. All is good after that. 

I suspect the tank did not need changing, but hard to prove. Lesson learned, I should have changed the SCR tank myself ($1500 part). The Nox sensors change requires the computer to be reset (like the battery).


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## PROEASY (Nov 17, 2015)

I would have some heart ache with that, seems the Nox sensors were the issue,,, how long ago, write BWM


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## Doug Huffman (Apr 25, 2015)

Depends on how the work authorization order was written. How it could have included the opportunity to assert “bad fluid.”


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## HotGrbg (Apr 23, 2021)

The DEF tank has level and temperature sensors only. The fact they replaced the tank due to the fact it has the “wrong fluid” doesn’t add up. You most likely had either level and or temp faults as well as there is nothing in the tank or to do with the tank that deals with fluid metering or type. There is a unit on top of the active tank but it’s not part of the tank.
It’s probably too late to do anything but I would buy a scan tool that gives BMW codes so you don’t go blindly into anywhere. You may not know 100% what the codes mean but BMW codes are pretty descriptive and there is PLENTY of information online.


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## PROEASY (Nov 17, 2015)

I was very clear to them that I know my way around a car, and only used BMW or Peak DEF, and was clear, only good DEF was added. Told them to pull up my parts history at their store (here in Detroit) and one in Nashville, where I would buy def when low (the 1,000 mile warning


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## PROEASY (Nov 17, 2015)

My scan tool (Schwaben) would not reset this code


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## HotGrbg (Apr 23, 2021)

It will not reset without a successful SCR system test being completed so yeah even BMW dealer tools can’t reset that light. Do you have your codes list? Was your only fault for wrong fluid or was there other codes?


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## PROEASY (Nov 17, 2015)

Do not recall the code, was as I recall a DME error or something like that: PS i fabricated a "BMW DEF Funnel" from one the BMW two liter bottles that screw into the DEF filler Neck


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## HackMech (May 5, 2021)

My issue just happened this past month 4/2021. I have an Autel Scanner. It reads intermittent tank level code. My fault since I had filled to the max a month ago, but the scanner can clear that warning. The Nox codes I also got were 26F500 and 26F600, which one can find BMW service bulletin 011918 for the repair. It's a warranty repair, so off to the Stealership I went. Their Bad fluid call is from a refractometer test. I got the $20 tool from Amazon. Shaking out the remaining two ounces of fluid from my old tank (I requested return), the damn fluid was on the money (32.5). So I knew the "bad" fluid was BS. The idiot car can only measure DEF fluid quality from the Nox sensors. When the Nox signal goes bad, BMW logic is to immediately blame the fluid and not the sensor.

The bad fluid codes can only be reset using BMW ITSA program. ebay to the rescue. My copy is in the mail.


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## mjez (Jan 16, 2014)

Sounds like it would've been cheaper to just delete and tune. 

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## HackMech (May 5, 2021)

mjez, recommend anyone to do the delete work in the northeast?


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## mjez (Jan 16, 2014)

Unfortunately, no. I'm in the midwest. But it's not that difficult to DIY and it saves ton of money too

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## Doug Huffman (Apr 25, 2015)

HackMech said:


> mjez, recommend anyone to do the delete work in the northeast?


It is a federal crime to accept payment for emissions deletion.


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## ard (Jul 1, 2009)

Doug Huffman said:


> It is a federal crime to accept payment for emissions deletion.


Indeed. SOme guys with a massive online- youtube, FB- presence that were modding diesel trucks got absolutely HAMMERED recently.


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## ard (Jul 1, 2009)

OP, dealeer will almost surely insist on drain, refill and flush of DEF. REFUSE this, unless he can provide third party analysis of the DEF fluid that shows it doesnt meet spec.


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## HackMech (May 5, 2021)

HotGrbg said:


> The DEF tank has level and temperature sensors only. The fact they replaced the tank due to the fact it has the “wrong fluid” doesn’t add up. You most likely had either level and or temp faults as well as there is nothing in the tank or to do with the tank that deals with fluid metering or type. There is a unit on top of the active tank but it’s not part of the tank.
> It’s probably too late to do anything but I would buy a scan tool that gives BMW codes so you don’t go blindly into anywhere. You may not know 100% what the codes mean but BMW codes are pretty descriptive and there is PLENTY of information online.


HotGrbg, 

2014 and later 535 has gen 2 SCR system. For Gen 2, there is only one DEF tank and intergrated into it is an ultrasonic level sensor, heater and forwarding pump. The ultrasonic unit and heater is internal and plastic welded in place, so there is no way to physically check or change. The pump is also integral to the tank, luckily it can be removed externally with three screws. In my research, I found the pump motor is engaged with a solenoid. Are there any experts out that that can provide insight on how to bench test the pump with jumpers? There are four pins in the pump. I assume two are for the motor and two are for the solenoid. Through my research, if the DEF tank is filled so there is no air space at the top of the tank, the ultrasonic level system will error as zero level (since it's not seeing a top liquid level).


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