[dixy2k]

I could delete the codes again after the fix, just have to work again on the reediness codes. I've done it once...

Will try something else this week and if it works, I'll probably have to do your mod soon after.

[dixy2k]

Does anyone have a more detailed process of doing this hack?
Looking at the pictures and reading some of the write ups, still leaves some questions in my case.

[montr]

Originally Posted by dixy2k

Does anyone have a more detailed process of doing this hack?
Looking at the pictures and reading some of the write ups, still leaves some questions in my case.

If the problem is the temperature sensor (likely part to fail), it is easy. You need to disconnect the connector to the sensor in the tank and instead connect a 10K ohms thermistor. The thermistor has 2 wire and no polarity. The hardest part of this job is to get to the connector.

The original poster can correct me if I am wrong. It circled the connector in question. The two wires for the sensor are the black and white at top. They appears to be smaller.

If the sensor in the tank is an open circuit, there is no need to cut the wire. You can just jump the thermistor across in parallel. To determine if the sensor is an open circuit, you need a digital multimeter.

[QUIKDZL]

Originally Posted by dixy2k

Does anyone have a more detailed process of doing this hack?
Looking at the pictures and reading some of the write ups, still leaves some questions in my case.

I'll happily mail you the thermistor you need--just PM your address to me. Once you remove the trunk floor, it gets pretty easy. You can see the electrical connector in the photo. It has four wires going through it. The two larger wires are the heater, and the two smaller wires are the thermistor. If you don't want to go inside the tank, just cut the two small wires on the tank side of the connector and splice the new thermistor to the small wires coming from the connector. You can secure the thermistor at the wiring harness or bond it to the tank if you like.

If you want to put the new thermistor in the tank like I did, you'll have to remove the active tank lid by disconnecting all the electrical connectors and hoses, and then unscrewing the large ring nut that attaches the lid to the tank. The lid will then slide out of the tank with a little wiggling and pulling. You will likely want to rinse the tank top clean of dried urea and dust before removing any of the tubes or connectors.

I was able to fish the thermistor leads through the grommet that the existing thermistor and heater wires go through by lubricating a small screwdriver with silicone grease (vaseline will do) and stretching the grommet a little while lubricating it. I then pushed the wires through from the inside by holding them with needle-nosed pliers about 1/8" from the end and pushing them into the grommet. You can push the wires through in very short increments. Once through, it's easy to pull from the outside. Next, reassemble the tank components. All connections can only fit one way.

If it's removing the trunk floor that's causing hesitation, you should have no problem if you're one who can change his own oil/tires/brakes, etc. You'll need to get the rear of the car up on ramps or jack stands. Remove the two nuts that hold the exhaust system mounts to the differential housing. I think they are 19mm. Then remove the two nuts that hold the exhaust system mounts near the front of the urea tank/rear of the tires. I think they are 13mm. At this point, the only thing holding the back half of the exhaust system up at the rear of the car are the two rubber hangers at the tips. Slide the rubber hanger off the horizontal mounting rod (over the ball end) at each tip and lower the exhaust system until it hangs on the front and mid mounts. It will drop about three inches.

Next, remove the heat shields between the mufflers and the urea tank. A 10mm wrench/socket will remove all the stamped hat-shaped nuts and an 8mm socket will remove the screws around the perimeter. Let the heat shields drop and lay on the mufflers. Don't worry if you need to bend them a little--they bend back easily.

Next, remove the two nuts that hang the urea tank from the trunk floor insert. They are located immediately above the mufflers on the bottom of the tank, and I think they are 19mm. The last thing to remove from the bottom is the plastic 10mm nut that fastens the battery cable tray to the trunk floor pan. It is located at the front passenger side of the urea tank near the battery.

Finally, remove the trunk floor pan by removing the ten 10mm nuts around its perimeter, and the plastic fascia that protects the trunk latch and tail lights. There are four plastic rivets that are removed by prying the pin out of the center and two phillips screws under oval caps that can be removed using a small screwdriver or pocket knife. Now you can pull/pry the floor pan up and see the top of the urea tank. Installation is the reverse of these steps.

Sorry I didn't take photos as I went along, but other forum members had already posted good photos of these steps. Let me know if I can help further.

[QUIKDZL]

Montr is right, except that I heartily recommend cutting the wires and splicing on a new thermistor. My sensor was open BUT INTERMITTENT. This caused the SES light to come back on ocasionally (when the sensor decided to work for a moment). Cutting the original sensor out of the circuit fixed this permanently.

[dixy2k]

The codes I get are P0205B and P0205C.
I forum member said this is what I have:
492C Reduktionsmittel-Aktivtank Temperatursensor, Plausibilität

46F9 Reduktionsmittel-Aktivtank Temperatursensor, Signal

I guess my codes (Torque) are some generic ones and they hide the real problem 492C and 46F9.

I have no clue. I'm not educated in OBD diagnosis.

If this is what you guys had, then I'll bite the bullet and do the job by myself.

[QUIKDZL]

Yeah, my codes were 46F9 and 4D32. Good luck.

[dixy2k]

Originally Posted by QUIKDZL

I'll happily mail you the thermistor you need--just PM your address to me. Once you remove the trunk floor, it gets pretty easy. You can see the electrical connector in the photo. It has four wires going through it. The two larger wires are the heater, and the two smaller wires are the thermistor. If you don't want to go inside the tank, just cut the two small wires on the tank side of the connector and splice the new thermistor to the small wires coming from the connector. You can secure the thermistor at the wiring harness or bond it to the tank if you like.

If you want to put the new thermistor in the tank like I did, you'll have to remove the active tank lid by disconnecting all the electrical connectors and hoses, and then unscrewing the large ring nut that attaches the lid to the tank. The lid will then slide out of the tank with a little wiggling and pulling. You will likely want to rinse the tank top clean of dried urea and dust before removing any of the tubes or connectors.

I was able to fish the thermistor leads through the grommet that the existing thermistor and heater wires go through by lubricating a small screwdriver with silicone grease (vaseline will do) and stretching the grommet a little while lubricating it. I then pushed the wires through from the inside by holding them with needle-nosed pliers about 1/8" from the end and pushing them into the grommet. You can push the wires through in very short increments. Once through, it's easy to pull from the outside. Next, reassemble the tank components. All connections can only fit one way.

If it's removing the trunk floor that's causing hesitation, you should have no problem if you're one who can change his own oil/tires/brakes, etc. You'll need to get the rear of the car up on ramps or jack stands. Remove the two nuts that hold the exhaust system mounts to the differential housing. I think they are 19mm. Then remove the two nuts that hold the exhaust system mounts near the front of the urea tank/rear of the tires. I think they are 13mm. At this point, the only thing holding the back half of the exhaust system up at the rear of the car are the two rubber hangers at the tips. Slide the rubber hanger off the horizontal mounting rod (over the ball end) at each tip and lower the exhaust system until it hangs on the front and mid mounts. It will drop about three inches.

Next, remove the heat shields between the mufflers and the urea tank. A 10mm wrench/socket will remove all the stamped hat-shaped nuts and an 8mm socket will remove the screws around the perimeter. Let the heat shields drop and lay on the mufflers. Don't worry if you need to bend them a little--they bend back easily.

Next, remove the two nuts that hang the urea tank from the trunk floor insert. They are located immediately above the mufflers on the bottom of the tank, and I think they are 19mm. The last thing to remove from the bottom is the plastic 10mm nut that fastens the battery cable tray to the trunk floor pan. It is located at the front passenger side of the urea tank near the battery.

Finally, remove the trunk floor pan by removing the ten 10mm nuts around its perimeter, and the plastic fascia that protects the trunk latch and tail lights. There are four plastic rivets that are removed by prying the pin out of the center and two phillips screws under oval caps that can be removed using a small screwdriver or pocket knife. Now you can pull/pry the floor pan up and see the top of the urea tank. Installation is the reverse of these steps.

Sorry I didn't take photos as I went along, but other forum members had already posted good photos of these steps. Let me know if I can help further.

The DEF tank hasn't worked in months. Probably all clogged up.
It is full of DEF but does not use it at all.

So getting to the tank is not possible from inside the trunk? I thought I saw someone take the trunk bottom out (the black plate) to get to some wiring.

Did I make the wrong assumption here?

[QUIKDZL]

You will access the tank top from inside the trunk, but you can't remove the trunk floor until you remove the two large nuts from the bottom of the tank. The tank is literally hanging on the floor plate, so it will not lift out until the urea tank is dropped. It will only drop a couple of inches.

Don't neglect to remove the plastic battery cable tray nut--it will prevent removal of the floor pan, or break the cable tray.

[dixy2k]

Thanks for the tips.
I never took it apart, so it's all new to me.
Besides oil and filter changes and the EGR plates I never did anything on this car. It seems way too complex for me to work on.

[QUIKDZL]

This mod is not complicated or mysterious, just a lot of steps to get to the heart of it. I would not have attempted it until I read the experiences of some pioneering forum members that had already done this. Their experiences and photos led me to understand what was required and that it was not too difficult for me. My car is a daily driver so I can't be without it, and this information led me to believe it was about two hours to get to the urea tank top. It was. The fix was quick, and the reassembly took about an hour.

[murat335d]

Hi All,

I have the famous P205B code. Form what I understand, the faulty temp sensor is in the module, located at the bottom. Can anyone confirm this?

If that's the case, does anyone know the part number of this module? The reason I'm asking is, I have a sample module (by luck) made by the same manufacturer, but I don't know if it will fit to my 2011 335D. Any help is appreciated.

[QUIKDZL]

The temperature sensor is at the bottom of the level sensor rod. I could not find a way to get the "heart" of the active tank out, but the thermistor I used was a definite cure. You would not even have to put it inside the tank if you don't want to. I can't imagine the tank lid ever being too different from the urea temperature in Tennessee. It will only be colder after the urea tank heater comes on, which would cause the heater to operate longer than necessary.

Putting the thermistor inside the active tank is not a big deal once you get the trunk floor pan out of the way. You can have my spare thermistor if you like.

[335dlci]

Would this work for those with prime?? http://www.amazon.com/THERMISTOR-NTC.../dp/B00SDT4TB6

[QUIKDZL]

Yes. That thermistor with long leads is perfect.

[montr]

Originally Posted by 335dlci

Would this work for those with prime?? http://www.amazon.com/THERMISTOR-NTC.../dp/B00SDT4TB6

Here is a waterproof one: http://www.amazon.com/Waterproof-Tem...GJW4K2DMHWM7XF

[335D Alpha Pappa]

You will need the waterproof one. The one from quikdzl was not immersion proof per the datasheet.

I just got this code so I was looking for one in a metal case to offer some protection from getting crushed by the urea ice.

[Frediesel]

This procedure would take care of the temp sensor, correct? What about the level sensor? I have the following codes...

Reducing agent active tank level sensor signal sensor monitoring error
Code: 004BAC

Reducing agent, active temperature sensor, plausibility to low tank temperature to ambient temperature Code: 00492C

I was planning on shipping my tank out to xemodex, but would prefer to keep a few hundred in my pocket and complete the work in a fraction of the time.

[QUIKDZL]

Yes, temperature sensor only. The level probes are simply metal rods of different lengths with wires attached at the top. These wires are the ones going to the plug at the top of the active tank. Since the urea solution is conductive, the urea completes the circuits between the reference probe and the low, medium, and high level probes. If the car is seeing an error here, there can only be three possible problems.

1) At least one of the level probes has broken loose from its wire.
2) The active tank is completely empty.
3) A connector or wire from the tank to the computer has failed.

Simplest troubleshooting method is to gain access to the top of the tank and unplug the connector that has four equally sized wires. Using an ohm meter, measure and record resistance across wires 1-2, 1-3, 1-4, 2-3, 2-4, 3-4. If all is working well and there is some urea in the tank, your readings should be either open circuit (infinity), or very low. Infinity indicates urea is not touching both of these probes, and low (and consistent) indicates urea is touching both of these probes. For example, if wires 1-2, 1-3, and 2-3 are all showing low values, then urea is contacting the reference probe, low level probe, and mid level probe, but not the high probe. You get the idea.

If you fill up the active tank (use urea only), you should get the same low resistance reading across all wire pairs. If so, the problem is not with any of the probes--check/clean all wiring and connections from the tank to the computer.

If the tank is dry, your transfer pump system is not working, and I can't help you there.

If a probe is broken off, I'd say a new tank is in order unless you can figure out how to take the guts out and repair/replace them. I could not see how to get the guts out, nor find parts to replace them.

[QUIKDZL]

Can xemodex repair them?

[QUIKDZL]

The final thermistor I used, btw, is submersible. The junction is at the end of 18" wires and dipped in black epoxy. Virtually indestructible.

[Frediesel]

Originally Posted by QUIKDZL

Can xemodex repair them?

The site states, "Our repair process resolves internal malfunctions, including code, 4D32 active tank, temperature sensor plausibility, and code 46F9 heater and temperature sensor."

When I emailed my fault codes, their response was...
"I have confirmed with our technicians that yes; our repair process will resolve the issues you’re currently experiencing with your SCR container.

I think I'll order the thermistor first so that I can have it ready in case the information you provided helps me resolve the level sensor issue. If it's beyond that, I'll go with Xemodex. I think I'll be tackling this project next weekend. Thanks for the info.