OBD Port Pin 15 -> ECU Pinout

[JoshH]

Hi all,

Stupidly (don't ask why!) on my m52b28 loom I removed the White/yellow stripe wire from pin 15 on the obd port when doing my loom - think I got s little confused when removing the abs unit connector!

I think pin 15 is a comm line for obd so code readers/ecu reading software doesn't work!

I tried patching a wire from pin 15 to the one and only white/yellow stripe wire going into my ecu plug but this causes the car to not hold an idle...it'll instantly die when connected so I'm guessing that's not the wire I need to patch to!

I've looked for ecu pin outs and pin 88&89 are comm lines but I can't find a Pinout for the obd port connections!

Most online info is bloody American and incorrect

[JoshH]

Yes sorry I was referring to the 20 pin diagnostic port. I always thought OBD was 'on board diagnostics'!

I have opened up the x6000 ecu plug and pin 87 is a red/white striped wire. I patched a lead from pin 15 D100 to Pin 87 x600 and still get a no comms error

Seeing as the wire changes from white/yellow to red/white at some point in the loom I have perhaps bypassed something by running directly from pin 87 to pin 15?

Looks like I am going to have to remove the loom from the car and strip it down

Thankyou for your help as always Will!

[HairyScreech]

Ah, this I may be able to help with.

First off what ECU/loom combo?

Where are you based, if your local I could probably come take a look.

The issue I think your having there Will is that the Siemens ECU uses a combo of OBD and the older ADS 20 pin connection. So it looks like those diagrams might be pissed. Certainly the ones I have here are different.

The Data Link Connector as it is marked on the diagrams is D100

D100 Pin 1 - ECU Pin 36 - SW
D100 Pin 2 - D110 OBD port pin 7 - WS/VI/GE
D100 Pin 4 - Fuse F48 15A - SW/VI/GE
D100 Pin 14 - 12V at all times - RT
D100 Pin 17 - ECU Pin 88 TXD 2 - WS/VI/GE
D100 Pin 18 - ECU Pin 60 PGSP - GN/BL
D100 Pin 20 - Tranny Module Pin 88 - WS/VI

Are you sure pin 15 is connected?
As you say D100 Pin 15 would be a WS/GE com line from pin 87 on an older ecu but is not on some late M52 stuff if it used the OBD interface instead. Pin 15 is only connected if the car uses an ADS interface
I know there's a cross over with Z3s where my M52B28 1997 car uses the ADS 20 pin interface but E39s of similar vintage use the OBD. (and yes the 20 pin plug can work as an OBD output/plug)

What did your loom come from?

[HairyScreech]

Firstly - Note - For clarity all the cars are "OBD" the ADS is OBD1 but later cars are OBD2 and everyone just seems to use the terms ADS or OBD when it comes to the diagnostic connectors. There was no standardization and no 16 pin port until OBD2 came along.



Diagrams? I don't know, had them a while.

Try this link - http://www.filedropper.com/1996bmw318is ... tingmanual
(if anyone ever wants this re-upped then PM me)

So far it has proven to be correct, it is what I used for the M3.3.1 conversion. You want the MS41 for the M52, the MS is siemens and the M is bosch.
Easy way to spot the siemens ECU is the funny 5 volt crank sensors where all 3 wires go to the ECU.

Page 93 gives the pin 15 details for the DLC.
Pages 165 and 172 give the DLC connections specific to the MS41.

It covers the M1.7, M3.3, M3.3.1 MS40 and MS41 ECUs

Now I am pretty sure that none of the E36s had a standard 16 pin OBD port, but I believe they used the OBD protocoll via the 20pin port instead of the ADS for some cars.
Apparently the tell tail is the pin 15 on the 20 pin plug.
If there is a pin there then the car is ADS and if not it is OBD.

Pin 15 will be white/yellow and goes to pin 87 on the bosch ecu. (that is how my M3.3.1 is wired).
The MS41 has battery voltage on that pin.
However the older MS40 (M50B20?) uses pin 87 the same as the bosch ECUs.
Is that the switch over to OBD protocol? possibly as 1996 was the mandatory date for the US implementation of OBD2.

Shit load of tech info on the whats and whys, never understood a word of it and still dont - http://webcache.googleusercontent.com/s ... ient=opera

Googling "ADS vs OBD" comes up with a lot as well but all irrelevant to this topic.

[HairyScreech]

I have just had a thought - while the ECU is OBD2 compatible the cars body modules will still be ADS.

So Pin 15 might be connected so you can talk to the ABS etc.

Later cars after the E36 are fully OBD2 compliant so the body modules are OBD2 as well. E36 modules use the ADS still.

Looking at my version of the D100 pin 15 you should have that wire connected to pin 16 on the X20 plug and Pin 87 on the ECU, however we know the ECU you have is a special case and does not use pin 87 in the same way.

Connect that yellow/white to nothing as the E30 never had any ADS scan-able body/abs modules.
I honestly cannot think what you have it wired to at the moment but I would get it off there.

ECU Pin 87 the red/white needs to be 12v from the fuel injection relay (pin 87 by coincidence).

What are you trying to access the ECU with?
I think you are going to need an ADS adapter board like I need for the M3.3.1 and the M52 in my Z3.

[HairyScreech]

No, there is 100% the M52 pinouts and diagrams on that PDF,

Page 165 is 1210.17-00 and page 172 is 1210.17-07 both are the M52 diagrams.

Your data link page you posted looks different to mine?



Pin 87 is standardised as pin 15 data link on everything pre OBD2, pin 15 is used as the data channel for the ADS communication.

This means it should still be on an M52 engined E36 in order to talk to the body modules but the M52 MS41 ECU will not have pin 87 connected to the data link, pin 87 on the MS41 is 12v from the ECU relay.

At lunch I will pull off some images and table up the pinouts, it was pretty late when posting the info above, perhaps I did not explain well.

[HairyScreech]

Seriously don't chop pin 15 to the D100 and put it to 87 or 88 on the MS41, I have no idea what it would do.
On the other hand, do it "for science"?

I see the confusion on the data link diagram. All the ECUs have pin 87 as the data link bar the MS41. That data link diagram is over ridden by the individual ECU diagrams.
The DLC diagram is a generic with the specific module diagrams being the important ones.

Pin outs and colours came from the noted pages on the MS41 diagrams. The M50 is different as you say.

I think the big problem he is actually having is he has the wrong connector to match the car.
If he has got a basic 20pin to USB or Serial from Ebay then they will not work without an ADS interface inline, you can talk to full OBD2 cars with that but E36s need the ADS interface because of the language the body modules and ECU "talk" in.
While the MS41 is an obd2 ecu it sends its data in the language the ADS interface uses still. (otherwise you would have a really spastic set up where you needed one lead to talk to the car and one to talk to the ecu).

There should be no need for him to alter anything, he has no body modules to talk to via pin 15, so it will not cause an issue with coms.
Pin 87 was repurposed as a power feed on the MS41, it's a red hearing in this case.

It's kind of hard to discuss via text, the E36 is a change over mongral, I will grab the info from the Z3 which never had the M50, the only 6 pot fitted to the early cars was the M52 and the body modules are all E36 based. (I need the ADS converter to talk to my z3)

[HairyScreech]

http://www.filedropper.com/m52e36-z3dlc
Here is a abridged copy of the Z3 manual, the Z3 of this generation only came with an M52 or 4 pot, all the body modules are nicked from the E36 so it can be looked at like an M52 only E36.

The diagrams match what I had above and it shows the distinctions.

Need the OP to let us know what he is using to try to connect to the car, penny to a pound its his interface not the car.

To do my M52 Z3 I needed both a 20pin to OBD lead and then spliced a tiny ADS into it leaving an OBD2 port plug and another wire tail that had the tinyADS on it.

http://openlabs.co/projects/Tiny-ADS-Interface

[HairyScreech]

I think this may be the clearest way to show it.

[JoshH]

Hey guys,

Wow! Huuuuge amounts of info above, thank you so much!

There's no cheap eBay equipment being used here though..!

We used a 20 pin converter lead to standard obd2 port adapter used with a Bavarian Tech diagnostic cable and software and I get no comms.

Also using CMD master cable and software it will not read the ecu.

All of the above are genuine gear costing many thousands. The equipment connects to an e36 328i OK so I'm puzzled as to why it won't work.

I now know thanks to your help why I removed pin 15! I must have noticed that the wire went direct into the body connector (e36 version of c101).

Oh and for the science aspect. If pin 15 is connected to pin 87 the car starts and will not idle. Also the battery drains down when car is off!!

Thankyou for all your input and help

[HairyScreech]

Ok, interesting, will have to check out those things.

What I can tell you is I have been able to connect to both my M3.3.1 DME and the MS41 in the Z3 using a combination of the TinyADS board, a modified 20pin-OBD connector (TinyADS added as a second output tail and serial connector) plugged into a serial port on a laptop running INPA.
That includes all body modules of the Z3.

Do you know what versions of the ECU you have? MS41.0 MS41.1 or MS41.2? Wht car did it come out of?

Is the EWS connected or is it deleted in the ECU?

Looking at the cables you have it should work for the ECU but not for the body modules right?

I would put the arrangement back to stock and see if it will connect then.

The reason there is no Receive wire for the ECU is you put 12v onto the programming line and that turns the TX into an RX.
Not surprised a missing 12v feed causes odd running behaviour, White/red on 87 to 12v and the white/yellow just left hanging.

Any idea what white/yellow wire you tried wiring it to? I could not find another white/yellow for the ECU other than that one.

[HairyScreech]

Good spot, your right it is the ICV wire. Same colour on the older Bosch ECUs as well, should have known that as I had a piss about with mine figuring out which was the opening and closing coils.
Explains why the car would not idle with that connected to pin 15

Try it without doing anything to the white/yellow wire first. See what it does.

I think an ADS converter is still needed for the cross over cars as the ECU still talks in ADS language. Not in the standardised OBD2.

OP- your CMD stuff says it will work on the E36 323i and 328i but I am not sure that's right, the US cars had to be OBD2 compliant in 1996 but the EU did not, so US cars are fitted with a 16 pin OBD port and the ECU can spit out OBD2 codes but only a full BMW ADS interface can talk to it properly.

The Bavarian Tech diagnostic stuff sounds like it will work for the ECU at least as it connected to the E36. Did it have access to the body modules or just the OBD2 fault codes?
I am pretty sure without ADS you can only access the OBD2 codes and not the full ECU information.

I might undo the pin 15 connection on the Z3 temporarily and see if I can still get a connection.
Otherwise we need to work out what the pin 15 should give in normal E36 use.
I am trying to figure out what Pin 15 does, It seems it is the "L-line" http://www.osefactory.com/tools/k+dcan/ ... uction.pdf

The suggestion is it is only used to wake the modules and the K line is a 2 way bus.

Edit - more info here: http://www.bimmerforums.co.uk/forum/f99 ... ed-t85191/

Will - To program the MS41 you need to jump pin 18 on the diagnostic connector (PGSP) to 12v, this put the ECU into programming mode, you should then be able to flash it with a flash tool.
Never bothered to try this as I don't have a flash tool.

[HairyScreech]

Any joy with this?