DDE: Reducing-agent passive-tank fill level sensor

DougNBodie · 02-13-2023, 03:05 AM

Now that BMW sells a SCR Heater Assembly (BOS-F01C600252) for the DEF tank that has fill level sensors, a new heating element and temp. sensor...Has anyone replaced this and still get the fill level sensor code 4BCC or any other codes coming back on. My SES light immediately went off and my Foxwell NT-530 scan came up clean. I put everything back together and within 10 miles I got the same codes and the SES light was back. Any ideas on what to do next?

Tomnavigator · 02-17-2023, 04:30 PM

4BCC code is passive tank level sensor issue not heater issue. I would not expect replacing the heater to solve a 4BCC code.

DougNBodie · 02-22-2023, 04:55 PM

Quote:

Originally Posted by Tomnavigator

4BCC code is passive tank level sensor issue not heater issue. I would not expect replacing the heater to solve a 4BCC code.

The heater assembly has the fill level sensors in it.

DougNBodie · 03-15-2023, 06:08 PM

Quote:

Originally Posted by DougNBodie

The heater assembly has the fill level sensors in it.

Starting to hate working on my car. So Here's where I went wrong with attempting to fix the 4BCC code....FCP Euro said that the Active Tank Heating Assembly would take care of the issue because it had a fill level sensor in it. It does have a level sensor, but not for the passive tank, Obviously. So I bought a $350 part I didn't need at the time. Back to the drawing board

DougNBodie · 11-27-2023, 02:22 AM

Quote:

Originally Posted by Tomnavigator

4BCC code is passive tank level sensor issue not heater issue. I would not expect replacing the heater to solve a 4BCC code.

Fixed that code with a 10K resister in the sensor plug

sharkbait094 · 12-01-2023, 12:28 AM

Quote:

Originally Posted by DougNBodie

Fixed that code with a 10K resister in the sensor plug

I also have the passive tank level sensor error. Do you have photos of how to do this? I have seen other forum posts that describe the process (solder a 10k resister to a wire, poke holes with a hot needle through the harness and poke the wire into somewhere?). I am not completely understanding the process but have been chasing SCR codes for months and have eliminated 5/6 of them. This is the last one to go! Don’t want to have to replace the whole tank!

LowercaseD · 12-05-2023, 08:11 PM

I just did the 10k resistor fix yesterday but of course forgot to take pictures.it's a bit involved but very inexpensive.

First step is lower the exhaust
Remove the rear most heat shield bolts and lowered that
There are two 14mm nuts that have to be removed which detaches the passive tank from it mounting plate in the trunk.
Then remove the truck liner
And remove the plastic trim where the trunk attached
You will now see the plate with a whole bunch of 8mm (I think) nuts aground the edge. Once those are put you can remove the plate and you have access to the top of the passive Def tank.
Be aware that the Def tank can fall down if you push on it. There is nothing but friction holding it in place.
Now you can either put a 10k resistor into the black two wire plug closest to the trunk or strip the wires and soldier it in.

02-13-2023, 03:05 AM	#1
DougNBodie Private 27 Rep 92 Posts Drives: BMW 335d M Sport Join Date: Aug 2017 Location: Orange County , CA. iTrader: (0) Garage List 2011 BMW 335d [10.00]	DDE: Reducing-agent passive-tank fill level sensor Now that BMW sells a SCR Heater Assembly (BOS-F01C600252) for the DEF tank that has fill level sensors, a new heating element and temp. sensor...Has anyone replaced this and still get the fill level sensor code 4BCC or any other codes coming back on. My SES light immediately went off and my Foxwell NT-530 scan came up clean. I put everything back together and within 10 miles I got the same codes and the SES light was back. Any ideas on what to do next?
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02-17-2023, 04:30 PM	#2
Tomnavigator Private First Class 82 Rep 189 Posts Drives: 2010 335D, V-10 Touareg Diesel Join Date: Mar 2015 Location: Southwest Louisiana iTrader: (0)	4BCC code is passive tank level sensor issue not heater issue. I would not expect replacing the heater to solve a 4BCC code.
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12-05-2023, 08:11 PM	#7
LowercaseD New Member 0 Rep 13 Posts Drives: 2010 335d Join Date: Dec 2023 Location: New England iTrader: (0)	I just did the 10k resistor fix yesterday but of course forgot to take pictures.it's a bit involved but very inexpensive. First step is lower the exhaust Remove the rear most heat shield bolts and lowered that There are two 14mm nuts that have to be removed which detaches the passive tank from it mounting plate in the trunk. Then remove the truck liner And remove the plastic trim where the trunk attached You will now see the plate with a whole bunch of 8mm (I think) nuts aground the edge. Once those are put you can remove the plate and you have access to the top of the passive Def tank. Be aware that the Def tank can fall down if you push on it. There is nothing but friction holding it in place. Now you can either put a 10k resistor into the black two wire plug closest to the trunk or strip the wires and soldier it in.
	Appreciate 0 Quote