error 115

[eller]

error 115

bmw e46 318i m43.

cant clear the error.

thermostat is replaced,

outlet rad temp sensor replaced,

the temp sensor on the engine is also replaced.

engine is around 107c normal temp driving 80km/h

could it be coolant level sensor or a small leak. ? i think i might have a very very small leak at the upper coolant hose o-ring.

isnt it an electric error when the error cant be cleared?.

[328 Power 04]

May have to check your wiring from dme to thermostat. DME bank 3 pin 9, black wire, and DME bank 3 pin 43, green wire.

Also make sure to get a good brand thermostat.

[bmwdirtracer]

Abel, you need a bit of background:
https://www.bimmerforums.com/forum/s...tiometer-error

Abel, can you advise me the correct wording of code 115?

Eller, let's do this again: What are the wire colors at the engine coolant temp sensor and the thermostat?

[328 Power 04]

115 is error for control of the electric thermostat

[bmwdirtracer]

Thanks, Abel.

Eller, what color are the wires at the thermostat plug?

[eller]

They are Black and green.

- - - Updated - - -

Sorry for my Late anwser. Didnt get any notafications About youre messages.

[eller]

Thermostat green/Black

- - - Updated - - -

Radiator outlet temp sensor is green/Black and grey/black

[bmwdirtracer]

Okay, good - wires are the correct color. That, plus the fact that you can't clear the code, and the thermostat has been replaced, probably means that you have an open circuit (bad connection/broken wire) between the thermostat plug and the DME plug # 6003. The green wire from the thermostat goes to the pin number 43; the black wire from the thermostat goes to pin number 9 of the same plug.

Don't cut the wires to test them. Instead, unplug the thermostat plug, and unplug the CENTER plug of the DME. (You will likely have to unplug other plugs to get this one loose. Most of these DME plugs have a swivel release - push down the button, and swivel the lever upwards.)

Next, read the tiny numbers on the bottom of the DME plug, and count until you find pins 9 and 43. Put a sewing needle gently into the appropriate hole, then test continuity (ohms) / resistance between that needle and the appropriate terminal in the thermostat plug.

As an additional test, do a continuity test between the two terminals at the thermostat plug, while the DME connector 6003 is unplugged

All this testing should be done with the ignition off.

[eller]

thanks bmwdirtracer, you're a hero.... i'll return in a day or two with anwsers when i'm done testing the circuit.

[eller]

hello agian i did the test with a needle, and measured 0.1k ohm in both the black and green wire, i also tried the continuity test and it was good, the multimeter made the beep sound.

any suggestions ?

[bmwdirtracer]

It is crucially important that you always pay attention to the RANGE of the tester. You state above that you measured each wire to have 0.1 k ohms. K= 1000. Therefore, 0.1 k ohms would be 100 ohms, which would be a bad wire. If, truly, that's what the meter said, for each of the two wires, with the DME and the thermostat unplugged, then the two wires are probably shorted together, and both almost destroyed. However, this is pretty unlikely.

You need to be very careful when you provide information, though, because if you make a mistake in telling us the data, we will give you the wrong answer.

Let me assume (that's dangerous) that your reading was actually 0.1 Ohms, not kilo ohms. That indicates the wire is intact - not necessarily GOOD, but intact.

Therefore, either:
a)The pins of the DME are bent, dirty, or disconnected, or
b) the DME is bad, inside, or,
c) the thermostat you bought is faulty. (Is this an OEM thermostat? Did you replace it because you had exactly the same code?)

IF the temperature reading you're getting is actually correct, then the thermostat is bad., or you have another cooling system issue, or both.

Do you have correctly working factory fans?

[eller]

i set the multimeter to ohm and not k ohm this time, and i said 000.4-000,5 ohms on both wires.


i am measuring from the thermostat green and black wired plug to the dme plug. pin 9 and 43.
_______________________

i've seen another post on error 115 where they opened the dme up and found a burned circuit on the board.

_______________________

This is the thermostat: from MAHLE original. :
https://www.thansen.dk/bil/autoreser...roup=2600-2080

and yes i replaced it because of this exact code.

[eller]

okay i set the multimeter to ohm.

i then connect the black lead to the 43 pin at the dme plug pin hole with a needle, and the red lead to the plug at the thermostat pinhole
(green wire)

both plugs unconnected.



- - - Updated - - -

on both wires the multimeter says 004,3 ohm
using the above method

[bmwdirtracer]

Yes, you have EITHER a bad thermostat, or a bad DME, it would seem. Was the replacement thermostat an OEM part? Is the code exactly the same with the old thermostat?

[eller]

i didnt match the oem numbers

i think its an oem part, the website dosent say any about an oem number, but i found the same brand thermostat on another site and it has this oem number

Reference number OEM: 11531436042


isnt the oem number molded into the thermostat plastic ?

i dont have the old thermostat anymore :/

its probably the thermostat, i should have bought the thermostat that was twice as expensive maby ?

[bmwdirtracer]

That is, indeed a BMW part number. However, that doesn't mean that you have an OEM part. OEM stands for Original Equipment Manufacturer. I always look for an OEM part from a reputable BMW specialist supplier.

The crucial question here is: Did you have exactly the same code when the old thermostat was installed?

[eller]

yes the code always been there, also with the old thermostat

[bmwdirtracer]

Okay, personally I'm suspecting that you have an entirely different issue with the cooling system, like perhaps the water pump isn't working. I think perhaps the DME is setting that code because it's not seeing the temp drop when it tells the thermostat it should be open fully. However, the thermostat is only partly electric; it should still be opening mechanically, so I believe that your coolant isn't circulating properly.

Try this: Open the expansion tank, make sure it's full to the appropriate level. Have someone start the engine and rev it to ~2500 rpm while you look into the neck of the expansion tank. Do you see a little stream of coolant, jetting across the neck?

Test 2: Close the cap. Let the engine run for three minutes. Then squeeze the top hose, hard. Have the other person rev the engine to ~3000 rpm suddenly. Do you feel the hose try to expand?

[eller]

did the test, there comes a stream of water at the neck, and yes the hose expands when reving the engine.

[bmwdirtracer]

Hmmmm, okay, the water pump IS working then. Since you can watch the engine temp on your scan tool, can you also see the data for the lower hose temperature (usually referred to as radiator outlet temp). By the time the engine coolant temp sensor reaches ~97C, the bottom hose should also be showing at least 65C.

[ross1]

observed operating temp of 107*c ?

[eller]

~97C, the bottom hose should also be showing at least 65C.


bottom outlet hose shows 47f= 7C

i replaced the sensor radiator outlet sensor two times weeks ago, but i was the cheapest sensors they had.


probably the cheap sensor not working

[bmwdirtracer]

That's possible, but if you replaced it twice, the odds become reduced. Have you seen your fan come on? Do you have an engine driven fan, or just the electric one? Is the electric one in front of the radiator, or behind it?

If you haven't seen the electric fan blowing hard, when the engine's at 107 degrees, then either the fan is bad or the sensor (fan switch) in the lower hose is bad. If the car were in front of me, I'd use an infrared temp gun to check the temps of the upper and lower hose.

If you grab the lower hose, when the sensor's reading 7 degrees, does that number seem correct, or is the hose hot? If the hose is very hot, and the lower hose sensor is reading 7, the sensor is bad. If the lower hose is not hot, and the engine temp is reading ~ 100C, the coolant is NOT CIRCULATING. This could mean a clogged radiator.

[328 Power 04]

The error is for the control of the thermostat for sure. So that makes it a faulty thermostat, or bad wiring, or in the end, a problem with the dme itself.
If you're sure of your testing, there may be a fault in the driver for the thermostat in the dme.

[bmwdirtracer]

Eller, please know that Abel knows the computers and their codes FAR better than I ever will. He's clarified that the code you have is NOT being caused by the DME not seeing the temp changes it might expect. You have a bad thermostat, or a bad DME, if your wiring tests are correct.

However, you do also have a coolant flow issue, because your lower hose isn't getting warm. The thermostat is also a mechanical design, and it should be allowing flow long before the engine temp reaches 107C.

Given the cost of a DME and programming it to your car, vs. the cost of a thermostat (should be under warranty anyway), I'd have to advise returning your thermostat as faulty, and getting a new one. I have had a number of OEM parts be bad right out of the box....maybe, just maybe, you got one of those.

Otherwise, you're going to need a DME, AND you're going to still need to figure out why your engine's getting SO hot.

Do your fans work?


https://www.newtis.info/tisv2/a/en/e...ooling/Xw3xhPS