[Rodie]

Hi all -- car in question is a 2011 328xi....!

I received the error code in the image below (hope it shows up) which I believe is a thermostat stuck open error.

I ended up replacing the thermostat, which is a project (especially on a xDrive) that I don't intend to DIY again! That said, it did *not* fix my problem (car taking forever to heat up) nor did it prevent my check engine light from coming back on (I replaced the thermostat, reset the light, and then it comes back a few starts thereafter with the same error code).

I also checked the fuse for the thermostat in the glovebox (it was moved there, apparently, from inside the engine compartment late in the E90 production run -- 2010 I think).

Anyone have any idea on what to try next? Both the engine and the radiator have been recently replaced so I'm wondering if something isn't hooked up/plugged in but otherwise the car is fine. The wire going to the thermostat is clean, plugged in, and visually OK.

Any ideas appreciated. Getting close to taking it to the dealer and letting them sort it out (unfortunately).

TIA,
Rodie

[TunafishE93]

What thermostat did you replace it with?

[e90yyc]

Originally Posted by TunafishE93

What thermostat did you replace it with?

+1

Did you ensure the harness for the heating element was connected properly? (T-stat is map-controlled by DME.)

I believe the error you’re getting is “Map Thermostat.” I had this error and replaced mine (Behr) and now all is well. I too have xDrive. Wasn’t a fun job but I didn’t think it was too terrible.

[gbalthrop]

Originally Posted by Rodie

... 2011 328xi...
I received the error code in the image below (hope it shows up) which I believe is a thermostat stuck open error. [klemmt offen = Stuck Open ]...

Any 328i/xi built after 3/1/2007 has the MSV80 DME, as opposed to early MSV70 DME, so use that to Connect to DME (Engine > N52K MSV80). You will probably have SAME code, 2EF4.

1) What Engine do you have? N51 SULEV, or N52K ULEV? It makes a difference as to the correct Radiator, and also whether or NOT you have an ROTS (Radiator Outlet Temp Sensor) located on lower radiator hose, in addition to the ECTS (Engine Coolant Temp Sensor) located at the OFH (Oil Filter Housing) on front of head.

2) What Engine did you install as replacement, and what Radiator Part# did you install?

3) Is the original Factory DME installed?

If you provide the Last-7 Characters of your VIN, I'll check ISTA for engine from factory. Meantime, please use INPA to view the following screens, save ScreenPrints as JPG files and attach here. I attach examples of those screens to the next post.

A) INPA > Functional Jobs > F2 Identification, showing ALL ~ 20 Modules in your vehicle with SGBD (Variant) of each. Do ScreenPrint and attach.

B) INPA > DME MSV80 > F6 Activations > F6 KFK Thermostat Activation. Do NOT press any of the Function Keys to Over-ride DME Control when you view this screen. Just watch it to see the ECTS & ROTS Values after the engine has reached normal operating temp, or about 10 minutes at idle. Do ScreenPrint and attach.

Consider the possibility that the engine actually DOES reach proper operating Temp, and that the Sensor input to the DME is erroneous due to Sensor, Connector or Wiring fault. INPA and an InfraRed Thermometer will determine if THAT is the case.

A "Tutorial" is attached with sample Functional Jobs Screens and instructions on HOW to save ScreenPrints of INPA or ISTA screens if you don't already know.

George

[gbalthrop]

Attached are:
A) INPA > Functional Jobs > F2 Identification. This screen shows ALL ~ 20 Modules in your vehicle
with SGBD (Variant) of each. Do ScreenPrint and attach.

B) INPA > DME MSV80 > F6 Activations > F6 KFK Thermostat Activation.

George

[Rodie]

I'll answer the easy ones and will need to do some more work with INPA on the others. I really appreciate these responses!

I replaced the thermostat with a Mahle replacement. Reading the label, it says "Suitable for BMW TM 14 97" and also lists a number below that reading 70807848. It does look identical visually to the one I took off.

There is one plug -- if this is the 'harness for the heating element assy' -- then yes, I plugged it in and it is secure. If this isn't what you're referring to let me know!

George: I will get INPA back out and get the screen captures you're mentioning. Don't have them yet. The VIN is WBAPK7C52BA821958. The engine was replaced, but also from a 2011 donor vehicle (the engine went bad within 2 weeks of buying the car). I know it is an "N52" but I'm not sure of the variants (N52K, etc). The radiator I have no idea on but can inspect it. Essentially, the motor was bad -- salvage yard replacement -- and then the radiator leaked and it was replaced as well but none of the resulting paperwork I have identifies the MFG/model of the radiator.

Sorry not enough info from my end, especially with you taking the time and providing the detail you did! I'll get to work!

Rodie

[E92William]

Your vin is for a car with N52N. Unless you managed to somehow put in an N51 which you'd be able to tell right away because of the 3 stage manifold.

[Rodie]

I managed to get the Identification info (first image attached) but am having trouble getting the Thermostat Activation screen.

For that, I go E90 -> Engine -> MSV 80 but then don't see an F6 option for "Activations". F6 points to "Component Triggering" -- which may be the right thing -- but then I get a selection for "Activations1" or "Activations2" and inside those I don't see a specific thermostat option. I've attached images of those screens as well hoping you could guide me...!

Yes, the 2EF4 on the error memory for MSV80 (same as it read when I incorrectly selected MSV70).

I'm hopeful! Thanks for the replies.

[Rodie]

I think I found the proper screen. Two images attached:

Car ran for about an hour in the garage prior (work meeting and I forgot about the car!) and then I shut it down for about 5 minutes.

The first picture (thermostat at 14%) was pretty much upon startup. It creeped up to around 25-30% and then went to zero and pretty much stayed there (second picture).

Not sure if these help -- I don't really know what I'm lookin for!

Thanks,
Rodie

[MightyMouseTech]

Let me guess, your car is automatic? Sounds like your transmission cooler thermostat is stuck open. This is a 5 minute diag.

With the coolant FULLY cooled down, disconnect the lower coolant line on the cooler, and plug the hose. Then open the cap on the coolant expansion tank. If coolant comes pouring out of the cooler, you need a new trans cooler.

You won't be able to diag this fault electronically.

[gbalthrop]

Originally Posted by Rodie

I think I found the proper screen. Two images attached:
...The first picture (thermostat at 14%) was pretty much upon startup. It creeped up to around 25-30% and then went to zero and pretty much stayed there (second picture). Not sure if these help -- I don't really know what I'm lookin for! Thanks, Rodie

Hopefully we're "lookin" to learn something about how INPA works, and HOW the Cooling System works.
First, some thoughts about INPA which you have probably already discovered. Since INPA was originally in German, created by/for folks who spoke German, it is up to "Anglos" to understand the CONCEPTS the German technical Terminology/ Words conveyed to German-speakers. "KFK" is the German abbreviation for this Electronically-controlled (Map) Thermostat (KennFeldKuhlung = Map Cooling).

F5 Status = Live Data = Inputs received by Control Module (in this case: DME Engine Module)
F6 Activations = Triggering = sending a command to the Control Module to "Over-ride" Module control of a component. This tests the OUTPUT side of the Control Module, the wiring, connector, and component function. In this case, "Component Function" is simply voltage supply to the KFK "bulb heater", and NOT the mechanical opening/closing of the T-stat.

What you did when you viewed the KFK (Map Thermostat) Screen was simply OBSERVE Coolant Temp and DME control of the Thermostat HEATER element. That % value bar graph is NOT showing the mechanical position of the thermostat: Open vs. Closed. AFAIK, there is NO sensor or device such as a feedback potentiometer which sends any signal to DME regarding T-stat mechanical position.

You can "Over-ride" DME Control of the T-stat heater. ANY of the F6 "Activation" or "Triggering" screens allow you to Over-ride Module Control. In this case, note the "< F5 > back to DME" command you can select. That actually "RETURNS CONTROL of the component to the DME" or CEASES the Over-ride of DME Control.

When you open an F6 Screen, you are simply observing Live Data with the component still under Control Module Control, and can't hurt anything. HOWEVER, BEFORE you select ANY of the over-ride functions, READ the "Activation Condition" at the top of the Screen, and make sure you understand what you are doing. INPA has built-in programming that PREVENTS the user from executing a harmful Over-ride, at least in MOST instances. You could however use the Injector Activation Function improperly in such a way as to dump unburned fuel into the Cats and cause an issue, as ONE example of failing to READ/THIMK.

Here is my interpretation of the two INPA KFK Screens you attached:

1) Screen 1:
a) 14% "DME Activation" of the KFK heating element

b) 95.3C Signal from ECTS (Engine Coolant Temp Sensor) as received by DME. The "Correctness" of that value is determined by the condition of the Sensor, Connector & Wiring between Sensor & DME. When Temp issue arises, ALWAYS confirm/ calibrate reading using Infrared Thermometer. ECTS is on front of OFH (Oil Filter Housing).

c) 87.8C "Radiator Outlet Temperature". Note that on N52 engine there is NO Radiator Outlet Temp Sensor (ROTS). N51 and some others have such a sensor (2nd Coolant Temp Sensor). In the case of your N52K engine, the value that appears for ROTS signal as received by the DME is ALWAYS 7.5C LESS than the ECTS value. This is NOT based upon ROTS INPUT to the DME, since there is NO ROTS on N52K-engined vehicles. It is merely a Computed Value based upon ECTS signal as received by DME.

2) Screen 2:
a) 0% KFK Heater Activation by DME
b) 87C ECTS Signal as received by DME
c) 79.5C ROTS COMPUTED Value, 7.5C LESS than ECTS signal received by DME

If the 2nd screen is with engine continuing to idle AFTER the 1st Screen was saved, I CANNOT account for the 8.3C DROP in ECTS signal. Obviously the Thermostat is NOT mechanically stuck OPEN, or it would NOT have reached 95.3C in 1st screen. WHY did ECTS value drop 8.3C, with NO KFK heater Activation?

Your Fault Code is "2EF4". The ISTA Definition for that code is "DME: Map Thermostat, mechanism" which suggests a mechanical fault with thermostat standing/ stuck OPEN. However, based upon your FIRST screen, that does NOT appear to be the case. Since we don't know the Algorithm for that code, we can ONLY guess it is based upon ECTS signal as received by DME.

Bentley has a DIFFERENT definition for the 2EF4 Code, and based upon my concept of how the system works, that definition MAKES MORE SENSE:
P0128 | 2EF4 | Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

The FIRST thing I would want to do is determine if the "Coolant Temperature" value as shown is reliable. You have a "New-to-you" engine, and I assume the ECTS came with it. Due to the location and position of the ECTS, it would be EASY to damage it during removal/installation of engine. Same for wiring harness & connector. So I would use an Infrared Thermometer to determine if the Coolant Temperature signal as received by the DME (what you see in INPA) is accurate. IS Coolant Temp ACTUALLY Below T-stat Regulating Temp?

There may of course be other explanations, such as some internal issue with the T-stat or its control, where the bulb is heated WITHOUT that showing on INPA Screen, or mechanical sticking AFTER heating. You could always remove the connector from the Thermostat (DON'T remove the fuse, as that also powers the Coolant Pump Control electronics), and see if Temperature remains at proper level.

Please let us know what you find,
George

[Rodie]

George,

You should get paid for this level of explanation and detail. It is appreciated. That said, your brain is far larger than mine so I have some questions that will demonstrate that!

I saw some links you provided on another post about the thermometers to use to do what you recommend. I also see the location of the ECTS, right there near the oil filter. Is this as straightforward as getting the thermometer and pointing at the ECTS? I wouldn't think this would give a good temp, but what do I know!

Also notice that the ECTS itself is a pretty cheap part and appears to be just a "unplug/unscrew old", "replace with new" and bleed the system type of DIY. Is this really a <$20 thing (see link below) that I should just grab and drop in there just to see if it fixes the problem? Just looking for opinion here -- this is the one I was looking at:

https://www.ecstuning.com/b-febi-par...621433076~feb/

I'm not with the car right now, perhaps something is obvious with the wiring or visual damage but and I wish I could at least lay eyes on it now -- but alas, another day for that.

Thanks again,
Rodie

[Rodie]

MightyMouse --

Is this what you're talking about? And the highlighted portion is the hose to remove/plug and then see if the coolant comes out there when pulling the cap where I would fill the coolant?

Just clarifying...... thanks

[MightyMouseTech]

Originally Posted by Rodie

MightyMouse --

Is this what you're talking about? And the highlighted portion is the hose to remove/plug and then see if the coolant comes out there when pulling the cap where I would fill the coolant?

Just clarifying...... thanks

Yes, and yes. Whenever you get that code it is either the thermostat or thermostat in the trans cooler stuck open. The car is not warming up fast enough and throwing the fault. We start my checking the trans cooler as described above, if that's OK, we replace the thermostat. I think you are going to find the trans cooler is bad as you have already replaced the thermostat.

[gbalthrop]

Originally Posted by Rodie

... Is this as straightforward as getting the thermometer and pointing at the ECTS?... Also notice that the ECTS itself is a pretty cheap part and appears to be just a "unplug/unscrew old", "replace with new" and bleed the system type of DIY. Is this really a <$20 thing (see link below) that I should just grab and drop in there just to see if it fixes the problem?...

Hi Rodie,
Yes, an Infrared Thermometer reading should be VERY close, say +/- 2C, to the ECTS signal, IF the ECTS is OK and the Connector & wiring to the DME are OK. Most Infrared Thermometers have a Laser that confirms WHERE it is pointed, and if you get the laser beam on the HOUSING, next to the ECTS where it enters the housing, you are effectively measuring the Coolant Temp exactly where the ECTS is.

You can also use the thermometer to see when the Thermostat opens after cold start:
1) Point it at the Lower Radiator hose. IF the thermostat is closed, the Lower hose temp should be quite a bit LESS than the ECTS temp at the head as the engine warms. Due to NO flow through the radiator with closed T-stat.
2) When T-stat opens, in just a few seconds you should see a significant temp increase in the Lower Hose, as heated coolant from the engine begins to flow OUT of the Lower Radiator Hose Bib, INTO the T-stat & pump. Prior to opening, coolant went from the head to the pump via the "Bypass hose" that runs diagonally Down to Pump from the OFH.
3) The higher the Radiator Fan speed (stationary at idle), the greater the heat transfer (cooling of coolant) and greater the differential between the ECTS Temp and the Lower Radiator Hose Temp.

Whether using INPA, or simply using the thermometer and looking at/listening to the Fan, Coolant Pump, etc., you can hopefully devise some tests to diagnose the issue WITHOUT having to guess or throw parts. Same for measuring temp of hoses into/ out of the Transmission Cooler.

If I understood your prior post correctly, if you start cold engine, ECTS signal slowly goes to ~ 95C, but then DROPS ~ 8C? THAT should NOT happen, whether standing still or with air flow through radiator of moving vehicle. If that is a GENUINE Temp Drop (as opposed to intermittent ECTS Connector/ wiring/ Sensor), then SOMETHING is causing the Heat Transfer to change, due to change in Coolant Flow through Radiator or OTHER heat exchanger.

George

[Rodie]

George,

It's going to be a day or three to get the thermometer, et al -- but just to clarify on the two INPA screen shots with the temp. This was never a cold start, but I can do one. The sequence of events was:

• Started the car and let it idle for about an hour. You mentioned 10 minutes to 'get up to temp" but I started it, got a work phone call, and forgot about it for an hour.
• Couldn't find the right screen in INPA, so I shut off the car and posted that. Decided to try again, 5-10 min later, and started the car. That's the first screen shot. After about 3-4 minutes, that's the second screen shot.

Do the reading make more sense based on this sequence? I did nothing with a cold engine, but certainly can if helpful. Thanks for the other leads, will just take the time to get the stuff necessary to do them.

Thanks,
Rodie

[e90yyc]

Originally Posted by MightyMouseTech

Let me guess, your car is automatic? Sounds like your transmission cooler thermostat is stuck open. This is a 5 minute diag.

With the coolant FULLY cooled down, disconnect the lower coolant line on the cooler, and plug the hose. Then open the cap on the coolant expansion tank. If coolant comes pouring out of the cooler, you need a new trans cooler.

You won't be able to diag this fault electronically.

Great advice. My AT car also takes a bit longer than I would expect to heat up, but t-stat is new and no WP codes or issues to speak of.

Any chance of making the diagnosis with an IR thermometer by comparing inlet and outlet hose temps at the cooler? It’s not a big deal if not, but figure if I can do less work with same result then why not .

[MightyMouseTech]

Originally Posted by e90yyc

Great advice. My AT car also takes a bit longer than I would expect to heat up, but t-stat is new and no WP codes or issues to speak of.

Any chance of making the diagnosis with an IR thermometer by comparing inlet and outlet hose temps at the cooler? It’s not a big deal if not, but figure if I can do less work with same result then why not .

Glad to help. I suppose you could just check it by putting you hand on the outlet hose and see if it stays closed. We check it by removing the hose as it is outlined in a special PUMA measure for this fault. The DME can tell the car is not warming up properly, but it has no way of determining which thermostat is stuck open.

[Rodie]

Well, it took me longer than "a couple of days" to get back to this. It's been 15 degrees (F) here for some time and I just haven't had the will to freeze in the garage.

Finally a warm Saturday today. The temperature read with the laser thermometer (at/near the ECTS) was consistently about 10 degrees (C) lower than what INPA was reading. I did that quickly, didn't do a bunch of other things (lower radiator hose, et al).

I had already purchased the $12 replacement ECTS as I just wanted to have it just in case so I decided to replace it and bled the cooling system. (side note: at least I think I did -- the last time I did that I heard a bunch of gurgling but this time I didn't really hear much. I didn't really need to add much coolant at all -- only a small amount came out while replacing the ECTS so perhaps it just didn't have air to make the gurgling sound from before -- not sure). I actually did it twice just to try to hear something significant but didn't ultimately get that satisfaction.

The thermometer temp at the ECTS is now about 3 degrees less than INPA is reading. It does vary a bit depending on where I'm pointing it (it's a bit hotter to the right of the ECTS on the larger surface below the oil filter cap.

I reset the check engine light and will report back as to how this goes. Haven't had the chance to really drive around much but my wife intends to later today and it will normally be a few days for the CE light to come back on regardless.

Guess it's worth mentioning -- in addition to the CE light with the error code mentioned the other symptom I've been having is nearly zero heat for most of the time, especially when driving faster/on highways. In stop and go driving or if sitting and idling I seem to get heat just fine. Then it pretty much just "goes away" and the air is barley warm.

I haven't done anything with the transmission cooler thermostat yet, but if this doesn't change anything perhaps that is next......

Thanks all. Fingers crossed.....

Rodie

[kristovey]

Originally Posted by Rodie

Well, it took me longer than "a couple of days" to get back to this. It's been 15 degrees (F) here for some time and I just haven't had the will to freeze in the garage.

Finally a warm Saturday today. The temperature read with the laser thermometer (at/near the ECTS) was consistently about 10 degrees (C) lower than what INPA was reading. I did that quickly, didn't do a bunch of other things (lower radiator hose, et al).

I had already purchased the $12 replacement ECTS as I just wanted to have it just in case so I decided to replace it and bled the cooling system. (side note: at least I think I did -- the last time I did that I heard a bunch of gurgling but this time I didn't really hear much. I didn't really need to add much coolant at all -- only a small amount came out while replacing the ECTS so perhaps it just didn't have air to make the gurgling sound from before -- not sure). I actually did it twice just to try to hear something significant but didn't ultimately get that satisfaction.

The thermometer temp at the ECTS is now about 3 degrees less than INPA is reading. It does vary a bit depending on where I'm pointing it (it's a bit hotter to the right of the ECTS on the larger surface below the oil filter cap.

I reset the check engine light and will report back as to how this goes. Haven't had the chance to really drive around much but my wife intends to later today and it will normally be a few days for the CE light to come back on regardless.

Guess it's worth mentioning -- in addition to the CE light with the error code mentioned the other symptom I've been having is nearly zero heat for most of the time, especially when driving faster/on highways. In stop and go driving or if sitting and idling I seem to get heat just fine. Then it pretty much just "goes away" and the air is barley warm.

I haven't done anything with the transmission cooler thermostat yet, but if this doesn't change anything perhaps that is next......

Thanks all. Fingers crossed.....

Rodie

Did you ever find a solution to this? I have exactly the same fault. mine seemed to start after I swapped the Radiator....
Kris