[dano328xi]

The 2E85 fault code stands for electrical coolant pump, communication. The problem I'm having is that the coolant temperature is too low. It's usually around 70C when it should be around 95C. I thought it was the thermostat, so I replaced that. It didn't help. I plugged in the INPA to see what it says, and the thermostat stays at 0%. The water pump stays at 76.1%. The screenshot shows the thermostat at 2%, but I only saw that for a couple minutes and back to 0%. I tried changing to 90%, but it goes back to 0% after 30 seconds or so.
I get an error when I try to change the water pump duty cycle. any suggestions? I'm happy to change the water pump, but I'd like to be sure before I spend that much money. thanks in advance

[PichaDis11]

How the heck on earth did you receive a water pump code then attempt just replacing the thermostat?

You couldn't have it any more clearer; the code means the water pump is having issues.

[dano328xi]

Did you read my whole post? The water pump is pumping coolant. I don't know if it's failing. If I wanted to just replace it and maybe it solves the fault code maybe it doesn't, I would have replaced it already. You know how those fault codes are. They aren't exact. If you don't have anything more constructive to post, move on.

[Efthreeoh]

Looks like to me the ECU is unable to communicate with the water pump, so the pump is running in a default mode at a constant speed to prevent the engine from overheating, which is why the coolant temperature is too low. This would be an unusual malfunction of the control electronics, that to my recollection no one has previously reported, but it is a reasonable assumption that the pump would be engineered in such a manner.

I think the pump codes are pretty accurate. When I first discovered there were water pump trouble codes in May of 2011, code 2E81 was specific as to the exact mileage the pump had trouble and the the exact amount of deviation the pump speed was off from the maximum of 250 RPM.

[dano328xi]

Hopefully it is the pump. I'm putting the new one on tomorrow and will report results.

[Three_thirty_I]

This thread is actually pretty interesting, and possibly relates to my car's cooling issue. But the car has been on diagnostics so many times and never picked up error codes. I've also replaced the thermostat in the hopes that the over-cooling issue would be solved, no change. So I must have this checked again, with a fine tooth comb!

Good luck, hope this solves your car's problem. BTW, temp should then run typically around 105 degrees Celsius when in normal Eco mode - as I'm sure you are aware, these engines have various mapped operating temps based on driving conditions.

[dano328xi]

new pump, new thermostat, no fault code errors, but no heat. Still takes forever to heat up and rarely gets above 80C.

[dano328xi]

Anybody know what voltage that the thermostat should be getting? I could unplug the power to the thermostat and measure the plug pins while the car is running.

[dano328xi]

Originally Posted by PichaDis11

How the heck on earth did you receive a water pump code then attempt just replacing the thermostat?

You couldn't have it any more clearer; the code means the water pump is having issues.

I replaced the ignition/injector wiring harness that includes the wiring to the thermostat. Problem solved. Please stop giving advice. You suck

[PichaDis11]

Originally Posted by dano328xi

I replaced the ignition/injector wiring harness that includes the wiring to the thermostat. Problem solved. Please stop giving advice. You suck

I'm very sorry you feel that way. The process of your diagnostics seemed premature to begin with but We live and we learn. Surely not a common problem for that to happen to with our cars. Do you care to share with the rest of the board your findings as to why you had to replace those wiring?

[servantguy]

Originally Posted by dano328xi

I replaced the ignition/injector wiring harness that includes the wiring to the thermostat. Problem solved. Please stop giving advice. You suck

Hi dano328xi ,

I consider it a miracle your response popped up during my search! Having a similar issue, in that I have new alternator, coolant pump, and thermostat installed, but the only persistent bsd error codes involve 2e83, 2e84, and 2e85. Do you have the part number/link of said wiring harness you replaced, by any chance? I'd like to replace mine as these are the only persistent codes my ride is getting right now. I appreciate the assist.

[nashville_bill]

My son's 2006 330i has a 2E85 code, no other codes, and has no overheating issues. I guess I should check out the wiring in that harness. It looks like they cost about $400, so I'll either repair it or get one from a junk yard.

[Papush]

Originally Posted by dano328xi

I replaced the ignition/injector wiring harness that includes the wiring to the thermostat. Problem solved. Please stop giving advice. You suck

I realize this is an old post but I'm hoping you'll reply and help someone out in 2021 and perhaps beyond. My son is getting an error code 2E85 on his 328xi. What did changing the harness entail? Do you have a part number?

[e91Owner]

I wouldn't purchase a wiring harness without diagnosing the old harness first. That code can mean a number of things, but in essence it indicated that the pump is not performing to the parameters requested by the DME. In this case, the pump is the far more likely culprit, so do some diagnostics first.

[designguy96]

I’d like to know more about how to diagnose if it is a wiring harness or not. I have the same code, but when I look at the live data the cooling pump and fluid temps appear to be in range.

[e91Owner]

Originally Posted by designguy96

I’d like to know more about how to diagnose if it is a wiring harness or not. I have the same code, but when I look at the live data the cooling pump and fluid temps appear to be in range.

You have to test the wiring for continuity from the DME to the pump. Clean the connections as well and make sure they are secure. The code itself is shorthand for you're not doing exactly what I'm telling you to do. While it may be the wiring, it's more likely the pump.

[maxxpine]

Does anybody solved this issues?
My Carly interface says missing coolant pump although is able to read all the parameters of the pump: RPMs, temperature, power etc.
Ista+ reports also the faulty code 002E85, saying it is a bsd bus communication error - see the attachment.
The engine has big fluctuations in temperature, from 70 to 120 degree without any pattern.
I replaced the thermostat but nothing changed. I wouldn't go yet for a pump replacement, could be this a harness issue? i observed that fuel pump has the same error as the one in attachment when I tried to trigger the ECU functions in ISTA+ , so it might be a bus issue, but I have no clue to solve it.
Any help will be welcomed. Thanks.