35d Reducing Agent Passive Tank Sensor Failure
 

Hi all,

Been lurking here for a few years and have found some great info. Thank you. I searched for my current issue, but didn't find much. Here's the problem:

'09 X5 35d. 59k miles. SES light on. Dealer diagnosis:

"Hooked up charger and performed a vehicle test. Found fault 4BCC for reducing agent passive tank fill level signal. Fault is currently present and has occurred 40 times. Followed test plan. Removed the undershield and checked connector at passive tank. Connector is OK. Test plan concluded the passive tank is faulty and needs to be replaced. Sensor is located in tank and tank needs to be replaced with sensor reading inside of it."

They recommend replacing the passive tank, part number BM16-19-7-22-146. $2,400 installed, out the door.

I declined repairs. Has anyone dealt with alternatives to replacing the tank to fix a faulty level sensor? If you did replace the tank, was it fairly straightforward?

Thanks!

Not emissions related warranty coverage?

Are you handy, if so, it is an easy fix:
X5 35d CEL P205b - Page 5 - Bimmerfest - BMW Forums

Dealer stated he checked and it's not covered under emissions warranty.

Awesome thread. Thanks for the link. That was focused on the active tank. I wonder if the level sensor in the passive tank (my issue) is the same as in the active tank (that thread).

The "SCR Reagent Reservoir" is covered under the California 7/70k warranty. Since they wrote the warranty and they failed to specify which of the two they are speaking about, it should apply to either tank.

So this applies obviously in CA, as well as any state which has adopted the CA warranty.....

Like those states that say "screw you" to emissions? Two edged sword.

LOL Like Wisconsin.

Minnesota too. If I have to spend much on my emissions it will be to go the "Lambeau" route...

http://www.xoutpost.com/bmw-sav-foru...ell-off-x.html

What was the outcome OP? I have same fault code.

I pulled the tank out and found that the low level sensor (bottom of tank) had 10k ohms resistance across the leads, but the high level sensor (top of tank) was an open circuit (infinite resistance) across the leads. You want 10 k ohms resistance across the leads of both sensors when the tank is empty.

I spliced/soldered a 10k ohm resistor across the leads of the high level sensor. I then shrink wrapped the resistor and wires, reinstalled the tank, and the check engine light turned off. That was 5 months ago - still no issue.

You could probably do the same thing without removing the tank as the leads to both sensors are accessible and visible at the bottom of the tank.

Definitely worth it to avoid paying the $1300+ for a new tank!