[flgfish]

I have a new to me 2012 E91 XDrive. I got the Bimmergeeks Pro Cable, and set up BMW Standard Tools and Rheingold in a Windows 7 VM. First time I ran ISTA+, there were tons of codes in several modules. Looks like the BMW techs that serviced the car for the first 7 years never cleared a code... so I cleared them all. Immediately, 2E85 (BSD waterpump missing) and 2E8B (BSD IBS missing) appeared. I checked the BSD connection on the battery IBS sensor and it appears physically fine. Then I had to take the car to run some errands, and when I got home, I ran ISTA+ again. At this point, 2E81 (DME, waterpump speed deviation) and 2E98 (BSD alternator missing) appeared as well.

My reading on this forum & others leads me to believe the 2E81 is a smoking gun for a waterpump dying. This doesn't appear to be measured via BSD, but via some other voltage signals - so I believe this code is probably true (not a BSD bus bad message or something like that). I have not experienced any excessive cooling fan noise, nor any temperature warnings or dash lights - just this 2E81 code, otherwise I would have no idea any idea anything was going on.

As an aside, the waterpump, thermostat & expansion tank were replaced in January of this year at a BMW dealership in Lincoln, NE. I have the maintenance receipts for the car.

It also seems that the waterpump going can sometimes cause the shared BSD bus to throw these other errors - the pump signal driver corrupting the bus, basically. I could probably prove this to be true by pulling the waterpump BSD connector, but before I put the car on ramps, shimmy under it and go to all the work of removing the undercover, I figured I'd ask the forum for your experiences.

Has anyone else experienced these symptoms? Do you agree this is probably a waterpump on the way out? How about the BSD faults, caused by the waterpump or unrelated? Any experiences or insights will help me greatly as I decide what I'm going to do.

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[flgfish]

I ran the car by my local BMW dealer, to get the service technician's thoughts. The service manager told me there's no way they could track it down without dash lights. I just raised my eyebrows & left. I guess this is the level of "give a shit" you get when Autonation runs your local dealership. Amazing.

[gbalthrop]

Originally Posted by flgfish

...new to me 2012 E91 XDrive. I got the Bimmergeeks Pro Cable, and set up BMW Standard Tools and Rheingold in a Windows 7 VM. First time I ran ISTA+, there were tons of codes in several modules. Looks like the BMW techs that serviced the car for the first 7 years never cleared a code... so I cleared them all. [Always read & record (as a JPG of Screen Print) (1) Fault Codes AND (2) Freeze Frame Data (including mileage/km at which Code was saved in DME or other Module, and whether the fault is "Currently Present") so you know history. Fortunately there is "HistorySpeicher" or Memory History in SOME Modules (DME, EKP, EGS) which remains for historical reference even if you cleared "FehlerSpeicher" or Fault Memory.]
Immediately, 2E85 (BSD waterpump missing) and 2E8B (BSD IBS missing) appeared...run some errands, and when I got home, I ran ISTA+ again. At this point, 2E81 (DME, waterpump speed deviation) and 2E98 (BSD alternator missing) appeared as well...the waterpump, thermostat & expansion tank were replaced in January of this year at a BMW dealership in Lincoln, NE.

I doubt that the water pump (8 months old) is faulty. The Speed Signal from the DME to the Water Pump is transmitted via the BSD bus, so if you have an intermittent fault in the BSD interface, you will have an intermittent 2E81 Speed Deviation, 'cuz the pump is NOT receiving the Speed signal on occasion. That's what the 2E85 code is telling you -- the water pump is obviously NOT missing "physically", just NOT proper response to/ receipt of speed signal from DME.

The reason I suggest you have an "intermittent" BSD bus issue is that if the coolant pump NEVER ran, you would have an overheating warning on the dash after driving for a few minutes. Here is the TIS schematic for the "BSD Interface" for your vehicle:
https://www.newtis.info/tisv2/a/en/e...rnator/oYPEvM2

If you have NO Fault related to the OZS (Oil Condition Sensor) which is the fourth component on the BSD Interface, that suggests the BSD Fault is intermittent, and has NOT occurred during Oil Level Reading. Try checking oil level after engine warmup. If the OZS works, then you had BSD bus function at that moment.

So it would appear that you do NOT have a component failure (if the IBS were faulty, you would see the Fault Code for that). You appear to have a loose connection or bad wire SOMEWHERE in the BSD bus (Violet wires) or connection from IBS to DME. If the Water Pump was the last thing worked on, (as opposed to Alternator, OZS or IBS @ Negative Battery Terminal), then disconnecting and cleaning its connector is the place to start.

INPA or ISTA will allow you to "Activate" the Coolant Pump to test for "Speed Deviation" between the Activation or "Over-ride of DME" speed selected, and actual speed. With INPA, you can select 5%, 50%, or 95% of max speed, and see what the "Actual" speed is. On my 2007 328xi E91, original coolant pump per Part# on pump, there is NO "deviation" at 5% or 50%, but it DOES
run @ 89% when 95% is selected. I've never had a cooling issue or Pump Fault Code (2E81 - 2E85).

I would suggest using Activation of pump to determine its health. BEFORE you activate it, NOTE the speed that it is running under DME Control, and if ~ 15% with Coolant Temp ~ 85C, then that is normal, at least for my N52KP.

I'll attach INPA ScreenPrints of "Water Pump Activation" Screen to the next post so as NOT to mess up margins here: (1) DME Control (NO activation selected) at 85C, and (2) Activation @ 50%. You may have to test continuity of BSD Interface wires, and/or Connectors at each of the 4 components, to correct the issue.

Please let us know what you find,
George

[gbalthrop]

Per prior post, INPA Screens, Water Pump Activation (F6 Activations), 2007 328xi N52KP, MSV80 DME.
(1) DME Control (NO activation selected) at 85C, and (2) Activation @ 50%:

[flgfish]

So I went out and played around with ISTA+ a bit, since I'm literally a novice with it. I did find that the DME reads 0 speed from the water pump. This can't be true, because coolant temperature levels are fine in the car.
I also found that iDrive reports oil levels as OK, so I suspect the oil sensor BSD connection is fine, but I haven't physically checked anything yet.

Is the speed read via BSD, or some other method?

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[ctuna]

Bsd line is shared between multiple devices.
One device corrupting the BSD bus can make the others
look bad.
You can see if the water pump will run by running the purge
procedure or there should be a software switch for in in Inpa or
Ista.

https://bmw.***********.com/threads/...ns-fault.4719/

* = ***********
s p o o l s t r e e t

From the search at google

https://www.google.com/search?client...0+bsd+problems

[flgfish]

I did some debug today. First, I unplugged the BSD connectors one by one, and cleared/read the codes in ISTA+.

IBS plug removed: Read IBS, Waterpump, Alternator BSD errors.
Alternator plug removed: Read IBS, Waterpump, Alternator BSD errors.
Oil sensor plug removed: Read oil sensor, IBS, Waterpump BSD errors. This is the only time I've seen an oil sensor BSD error, curiously enough.
Waterpump plug removed: Read waterpump, alternator BSD errors.

The car was running with the first three, but I only had the ignition on with the waterpump BSD connector unplugged. The reason for that, is that power is also supplied in the same connector as BSD, so I wasn't going to start the car without cooling. I think the alternator BSD error is probably caused by no power to the alternator without the car running - so it can't talk on the network, hence the error. I'm not sure of this, though.

The waterpump electrical connector was shiny & clean. No obvious external signs that would cause an issue.

ISTA+ is unable to tell the pump what speed to run at - it fails with a communication error every time. ISTA+ is also unable to read the speed the pump runs at - it always says that the pump is running at 0.

The waterpump is also clearly running. The coolant temp was about 85C or below at any time I read it, with the car off/on idling in the garage as I tested.

I think this indicated bad waterpump electronics. I'm hoping that gbalthrop agrees.

edit: the more I look at the wiring diagrams on Newtis, I think my alternator theory is wrong. I don't know what's going on now. Wiring issue or DME connector issue maybe? Shit.

[flgfish]

Just general research on the waterpump, so thought I'd write down what I'm seeing on Newtis and in the car.

The pump has the water inlet/outlets and one electrical connector. The electrical connector has four pins. The four wires associated with those pins are red, brown, orange and violet.

Violet: BSD bus
Red: +12V (electronics power) - fused @ F02 in the E-box
Brown: Ground
Orange: +12V (pump power) - fused @ F09 in the E-box

[gbalthrop]

Originally Posted by flgfish

...The four wires associated with those pins are red, brown, orange and violet.
Violet: BSD bus
Red: +12V (electronics power) - fused @ F02 in the E-box
Brown: Ground
Orange: +12V (pump power) - fused @ F09 in the E-box

It appears that you are looking at a circuit diagram related to a vehicle built BEFORE 3/1/2007, as it is is my understanding that the fuses for the Coolant Pump and Pump Control were no longer in the E-box after that date. F01 through F09 refer to fuses in the E-box and F-07 is the only fuse in the E-box on my E91 built 3/14/2007.

What I believe to be the correct TIS Engine Cooling System circuit for your 2012 328i X Drive E91:
https://www.newtis.info/tisv2/a/en/e...ooling/vFKjkjB

As I read that Schematic, Main Power to Pump is provided via fuse F33 which has constant Battery power (Terminal 30 per small "30" above fuse symbol) and provides constant battery power to Pin #1 of Connector X6035 via the Red wire. Control Circuit power for BOTH the Thermostat AND Coolant Pump is provided via fuse F37 which is switched by Terminal 87. The Orange wire from F37 to Pin #2 of Connector X6035 provides power to the Control Circuit for the Coolant Pump. Here is what TIS says about Terminal 87:

The DME/DDE controls terminal 87 via a relay in the E-box. Terminal 87 is switched on as soon as terminal 15 is switched on. After terminal 15 has been switched off, terminal 87 is switched off by the DME/DDE with a slight delay.

Here is everything you always wished you knew about "Terminal Control":
https://www.newtis.info/tisv2/a/en/e...gnosis/YEnzRWx

My SWAG is that your pump control circuit (internal to the pump) has failed in such a way that it is always running at a fixed speed when Terminal 87 is Active. I know that's at odds with what I suggested earlier, but after some thought, that's the ONLY way I can think of that the pump would be running and yet show "0%" speed on the screen showing actual speed when Activation is attempted, OR when you KNOW the pump is running without activation.

So making sure to stay clear of the E-Fan, turn on the ignition without starting engine, and listen for pump gurgle or hum. You can also remove Coolant Reservoir cap and watch for small stream of coolant coming from small hose across front of engine from Top Radiator Hose, to confirm pump is running. See if pump continues to run for a short time AFTER STOP button is pressed to turn off ignition. If pump exhibits that behavior, then it would appear the pump internal control circuit, controlled by signal from DME via Violet BSD line @ Pin #3, is NOT functioning.

Are you SURE that you don't have one of the Coolant pump codes 2E81 through 2E85 saved in the DME? I've forgotten/ NOT clear if one or more of those is STILL present?

I remember you stated the Pump & Thermostat were replaced January, 2019 by a Dealership and you have the receipts. If that was during the ownership of Prior Owner, Dealership may have installed a faulty pump. You might backprobe pin #3 of Connector X6035 (Violet wire) with ignition ON (Engine OFF) and measure voltage, and or Duty Cycle/ Frequency if you have a meter capable of that. I have NO IDEA what the readings should be, but someone may at least have some theories.

You might also disconnect the Violet wire at both Connectors, X6035 at the Pump, and X60007 at the DME (Pin #26), and test for continuity end-to-end (what you want), as well as for continuity/short to ground (what you DON'T want).

And YES, the Speed signal TO & FROM the Coolant Pump, in BOTH directions between Pump & DME is via Violet BSD wire AFAIK -- I would think that's why it's referred to as a bus.

Please let us know what you find,
George

[flgfish]

Originally Posted by gbalthrop

Are you SURE that you don't have one of the Coolant pump codes 2E81 through 2E85 saved in the DME? I've forgotten/ NOT clear if one or more of those is STILL present?

2E81 has shown up when I drive the car and read the codes later. It does not appear when I am testing the car in the garage. It appears to take some time to manifest. My assumption is that the DME has tried to tell the pump to go to X%, and later it tries to read it, that fails, and it throws the speed variation code.

I've used ISTA+ to clear the failure codes between all my test runs. There aren't any saved in the logs before I run the module test again to scan for codes.

I've never been able to get ANY pump value but 0 when reading it. It's always 0.

I remember you stated the Pump & Thermostat were replaced January, 2019 by a Dealership and you have the receipts. If that was during the ownership of Prior Owner, Dealership may have installed a faulty pump.

Yes, it was. And it was. I'm positive these codes were there when I bought the car, and the just didn't show up on the dash, so nobody did anything about it. Or they didn't know about it.

You might backprobe pin #3 of Connector X6035 (Violet wire) with ignition ON (Engine OFF) and measure voltage, and or Duty Cycle/ Frequency if you have a meter capable of that. I have NO IDEA what the readings should be, but someone may at least have some theories.

I have a standard cheap DMM here at home. The DME<>Pump BSD continuity test is "hard" because the leads are short, but I'm sure I could rig something up with wire. I was pondering this tonight, thinking about how I'd go about testing this with my cheapo DMM. I do have access to nicer O'scopes, but I'd like to not have to drag one out of the lab.

And YES, the Speed signal TO & FROM the Coolant Pump, in BOTH directions between Pump & DME is via Violet BSD wire AFAIK -- I would think that's why it's referred to as a bus.

Thanks, I had reached this conclusion after looking at the schematics. I read somewhere that the speed was calculating by comparing two different voltages (one before, one after the pump), but that has to be crap, or I just misread whatever that poster meant... I realize the wire can do 2-way communication, I just wasn't sure the water pump communicated speed that way (due to the forum post I mentioned, mainly).

It's probable that what I read was talking about an older pump, and I just misconstrued the year of the car they were talking about too... a mechanical pump could act as a genny, for instance, and you could measure speed if you had some copper wire and magnets in there with the pump rotor.... now that I think about that, I bet that's it.

[ctuna]

Did you look in the Ista + data base for
a BSD troubleshooting procedure?
Just do a search for BSD in Ista.
There might be a 0-scope procedure I think I have
seen somebody use it here before.

[flgfish]

Originally Posted by ctuna

Did you look in the Ista + data base for
a BSD troubleshooting procedure?
Just do a search for BSD in Ista.
There might be a 0-scope procedure I think I have
seen somebody use it here before.

I did nose around a bit, mainly through the dialogs it builds after you read the codes. I'll look around some more this week.

Based on what I've done so far, I see four possibilities.
1. It's the waterpump electronics, and the alternator is fine. I can't explain why the alternator BSD code showed up when I had the waterpump unplugged, unless it's not powered when the car's ignition is on but the car isn't running. I actually hope it's this.
2. It's both the waterpump & the alternator with BSD issues. Seems improbable but possible.
3. I have some BSD intermittent connection, and it's likely at the connector for the DME, or inside the DME itself. That's the only way I can explain the behavoir without bad endpoints.
4. I have multiple bad wiring runs or connectors. This seems like the least likely.

I tested the waterpump today some. When I turn on the ignition, the pump doesn't appear to turn on. There's no flow in the overflow reservoir tank.
When I do the bleed procedure though, the pump does turn on. There is visible flow.
I also did some driving and worked in higher revs, and the coolant and oil temperatures are all fine and what you'd expect. Here's a picture from ISTA. Pretty sure the battery voltage here is read through IBS - it always reads 0 when the IBS is disconnected.

View post on imgur.com

[flgfish]

Quick update. I did some testing with a DMM and all the wiring seems fine. I took the car to my local BMW indie, and they say to change the alternator first - I didn't realize it, but the previous owner had the alternator done at a non-BMW garage, and she got an off-brand alternator ... the tech at North Houston Beemer says he's seen lots of issues due to this brand of Autozone junk...

So I ordered a new alternator, and I'm going to replace it. Going to do the tensioner and belt at the same time.

It seems likely that I have both bad alternator & water pump on the BSD bus. I'll be shocked if changing the alternator makes the water pump issues go away.

[flgfish]

Replacing the alternator seems to have fixed all of the faults. I can't explain it, except for it being a source electrical issue, and not a controller or bus issue at all. When looking at the alternator voltage in the dash menus, it did bounce quite a bit under different loads. With the new Bosch alternator, no matter how I load or unload it, it's solid at 13.3-13.5 V seemingly all the time.

I replaced the belt tensioner at the same time, since that was original and needed to be done. I was going to do the belt as well, but the one that came off the car appears basically new, so I put it back on. Doing the alternator + tensioner took about 45 minutes in total, including changing the air filter, since I had the airbox off to get to the alternator.

This alternator was put on by a shop in NE. I don't know the brand or where they got it; I'm going to look around the web. It was a remanufactured alternator, of some off-brand... here are some pics of it.

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View post on imgur.com

Thanks to gbalthrop and ctuna for the input. I'll follow up if anything changes, but for now, it appears solved.

[flgfish]

Figured I'd follow up on this. Everything is still fine. BSD bus faults are gone. It was the alternator the entire time.

[bluesy_cube]

So strange how the alternator would cause a problem on specific area instead of wide areas. Glad that your car is back on the road.

[crosewing3]

Wow I had a similar problem and have been suspect an alternator since the codes are appear a time period within alternator replacement. Now I am pretty sure its the alternator since it is not BOSCH. Thanks a lot!!!

[DeobandiPrince]

Originally Posted by gbalthrop

I would suggest using Activation of pump to determine its health. BEFORE you activate it, NOTE the speed that it is running under DME Control, and if ~ 15% with Coolant Temp ~ 85C, then that is normal, at least for my N52KP.

I'll attach INPA ScreenPrints of "Water Pump Activation" Screen to the next post so as NOT to mess up margins here: (1) DME Control (NO activation selected) at 85C, and (2) Activation @ 50%. You may have to test continuity of BSD Interface wires, and/or Connectors at each of the 4 components, to correct the issue.

Please let us know what you find,
George

Hey George, it's me from the AC thread a day or 2 ago haha. You seem to be very knowledgeable about these things.

I have a solo 2E85 code (Just the one code. Nothing else.) Previous owner said the owner before him changed the water pump (in 2019 but no receipts were given.) Here's the freeze frame. I can't clear the code. If I try it doesn't even go away from the screen. It's always there.



The car never overheats and when I request various water pump RPM's it's all within range as noted below





Is there anything worth noticing in the data above?


My VCG, OFHG and oil pan were leaking badddd when I bought the car and so the whole front of the engine is greased up. The front of the water pump has enough that I took a long screw driver and just brushed off a layer of oil and dirt. The point of all of this is that I saw in another post someone mentioning that they had to unplug the water pump connector, clear the code and reconnect it. Maybe the oil and dirt got into the sensor or something? Considering that the pump request percent lines up with actual percent, do you think that hopefully just disconnecting the sensor, cleaning up the sensor, clearing the light and reconnecting it would fix it?

I should also note that there's nothing out of the ordinary from the fan. I've read people reporting that the fans go on full blast when they turn on the car or other weird stuff but nothing on my end. I can run the coolant bleed procedure with no issues or stuttering either.

Won't have my jack with me till the weekend so hoping to come up with a plan of attack till then.

Looking forward to your usual insightful comments.