My e38 was programmed to remove the 140 map cooling error for the 88c tstat for the missing sensor and hasn't thrown the error since. Some DME versions throw the temperature is too low some do not. My e38 never threw that error...

That's exactly what I've heard as well. I've heard it's possibly only 2003 build dates. Or 2002-3. My car has the Dinan S2 trans and engine reprograms as well. Not sure if that changes anything in regards to this.

I'm seeing the euro BMW part in stock at ECS for $120.
Sucks it's so expensive. But its really good piece of mind for me, and stupid simple.

I also like removing the possibility of having the DME slurp coolant up the cabling until it fries. I still don't understand how this is possible, but it definitely happens. (Never to me).

Mine is a DINAN S2 as well and I have been working with the same friend to get rid of the 140 map cooling error but being this is a bit different than the e38 and e39 and is also a DINAN. The error is still there so a little more tinkering has to be done in that regard. I havet ran 90c yet so I haven't thrown the temp too low error but IIRC he programs the DME to accept the lower temps as well as curving the aux fan to work for an 88c tstat...

Coolant simply starts to leak on the connector side of the heater element and it then creeps upstream with capillary action between wire core and cover. As the connector plug itself is supposed to be water tight the leak doesn't show out. Same thing can happen with oil or fuel pressure sensors on some models. Any connector can internally fail if there is pressurised liquid on the other side.

thanks! sorry i was unclear. i know HOW it happens.

by why wouldn't BMW put some type of bleed/drain hole in the cable shrink before it could get close enough to the DME to fry it? or just shorten it a tiny bit on the engine side and more so on the DME side?

obviously they didn't think to account for the leakage of the electrical components through the connector and into the cabling as these vehicles aged.

How would you make a wire with a "bleed valve" and still water resistant? The wire is not solid so liquid will also creep between the strands.

BMW didn't think/care anyone still using there products at this age.

I think the capillary action is happening between the heat shrink and individual copper conductors insulation. There are still some small voids in this to allow for capillary action.

Not sure it happens between the copper stranding and insulation in the individual cables that are then heat shrinked together. Cables typically done have the space between copper and insulation to act in this manner. I'm a low voltage engineer for 20 years.

Obviously copper must be insulated from connector to connector. So if liquid is travelling via this route there is nothing to rectify that.

So do the cables actually corrode away too?
I'd imagine coolant will destroy the copper and insulation over time.

My friend's 03 e39 540 had oil travel to the DME connectors from the vanos solenoids. Easier to clean than old coolant that will cause corrosion and kill the DME...

I ordered a new 88c thermostat from ECS for $115 shipped after taxes. I do watch my ktemps on each drive cycle(I know I'm nuts), so I figured its worth the piece of mine to rule out if the one I currently have in is in fact bad...

As these vehicles become more complex, little things like this will creep through. They cannot consider everything, all the time. Of course.

...and coolant weeping up a wire sheath....wtf?