On the mortality of cars

"If only EssExTee could be so grossly incandescent" (essextee)
04/18/2019 at 07:35 • Filed to: None

*UPDATE* the motherfucker worked ONCE. I’m so pissed. I got my bluetooth dongle to connect ONCE. By the time I went to get the good scantool that can actually read the airbag light it was back to being non-communicative.

I’m genuinely scared that my 528i is at the end of its useful life. Unless I can figure out this new OBD issue, it can never pass state inspection again. This car has been so great to me, and while I always figured I would be its last owner I’m not ready to let go of it yet.

I had mentioned the OBD issue in a previous post but didn’t describe it in detail. No scantool seems to be able to communicate with the car, either through the OBD2 port or the under-hood BMW diagnostic port. The cause could be anything from a bad ECU to a break somewhere in the ~5,000 feet of wiring this car has. Whatever it is, diagnosing it is beyond my knowledge and capabilities.

Internet’s been no help, when I try to search I just get people complaining about their bluetooth dongle not working. I however have tried two different devices, one of which I know worked fine with this car last month, so I know the problem is with the car.

My next step is to take it to a shop and see if their expensive scantools can come up with a different result. I haven’t been able to think of how I’ll go about asking for what’s essentially a free diagnostic though because that’s my budget right now.

Because of the mileage (265k) it’s worth next to nothing in trade-in. Edmunds says $300. With the current state of my finances I would have to take out a personal loan or a lease in order to get a new car. Either way, I end up in a cheap penalty box appliance that I’m going to abhor driving every day. I couldn’t pick and choose my next car, it would come down to “whatever I can afford”. As an enthusiast the thought of that distresses me greatly.

I can’t give this car up, I love it too much and have had too many great memories with it. I can’t have a car that I’m not going to enjoy.

This is putting me in a funk, Oppo.

DISCUSSION (34)

Mercedes Streeter > If only EssExTee could be so grossly incandescent
04/17/2019 at 22:08

I’m not sure if your exact model of BMW has one, but I know some cars do. Is there a fuse for the port?

And even if you can't fix it, I don't think the car has to die. It can live on in the hands of an Oppo in a state where emissions testing isn't a thing. :)

If only EssExTee could be so grossly incandescent > Mercedes Streeter
04/17/2019 at 22:10

I’ve already been through t he fuse box, and I’ve even taken a multimeter to the OBD2 port to make sure the grounds are good.

Future Heap Owner > If only EssExTee could be so grossly incandescent
04/17/2019 at 22:28

I know you’re on a smaller island, but if you could find a electronics hobby group, somebody might be willing to hook up an oscilloscope or logic analyzer to try to see what exactly is deviating from nominal (I assume there’s enough documentation on OBD-II, official or otherwise, to be able to determine what it should look like ). That would show a broken connection pretty quickly. But given the sunroof leak, plus the CEL... it could easily be a lot worse than that.

I’m sorry man, this is a crappy situation for sure.

gmporschenut also a fan of hondas > If only EssExTee could be so grossly incandescent
04/17/2019 at 22:29

Anyway to PB blast/kr oil up those lugs?

any way to swap out with a cheap used ecu?

https://www.ebay.com/i/323773714684?chn=ps

If only EssExTee could be so grossly incandescent > Future Heap Owner
04/17/2019 at 22:31

CEL cleared itself after a few driving cycles , and my cruise control re-enabled i ts e lf at the same tim e, so the light w as just the speed sensor after all. I’ve already disassembled the lower dash and OBD port. N o sign s of corrosion or water damage.

BaconSandwich is tasty. > If only EssExTee could be so grossly incandescent
04/17/2019 at 22:32

I was going to suggest checking grounds. Improperly grounded connections can cause all sorts of weird issues. Although it sounds like you already checked that. :(

Future Heap Owner > If only EssExTee could be so grossly incandescent
04/17/2019 at 22:34

Oh! The CEL going away is a good sign, that makes the bad connection hypothesis more plausible. I would definitely try to find some electronics dorks that might be able to help you out, then. Amateur radio groups would probably have access to oscilloscopes , too.

If only EssExTee could be so grossly incandescent > BaconSandwich is tasty.
04/17/2019 at 22:34

T he OBD2 port is grounded fine, but I couldn’t find any diagrams for the BMW port to tell me what to check, and the ECU itself could have a bad ground. Unfortunately I’m not very well versed in electrical and I’m learni ng how to use a multimeter as I go so it’s a slow process.

If only EssExTee could be so grossly incandescent > gmporschenut also a fan of hondas
04/17/2019 at 22:37

I want to rule everything else out before I try that. Forums say the ECU needs to be reprogrammed by a dealer, and after a certain build date they can’t be reprogrammed at all and you have to buy new.

itranthelasttimeiparkedit > If only EssExTee could be so grossly incandescent
04/17/2019 at 22:39

try getting a bmw can bus cable (forget if that is the exact name) and you can find INPA and such floating around on the internet easily. changed my life completely, 100x more powerful vs odb scanner. the cables are like $60, just research to make sure you’re getting a good one before you order. There is a lot of garbage out there.

If only EssExTee could be so grossly incandescent > Future Heap Owner
04/17/2019 at 22:40

Are the ama teu r radio groups gonna know how to use an oscilloscope to diagnose automobile electrical be cause I sure as hell don’t

ItalianJobR53 - now with added 'MERICA and unreliability > If only EssExTee could be so grossly incandescent
04/17/2019 at 22:40

Could you ship out your ECU to a shop for them to check it for issues?

I have a massive soft spot for E39s :((((

If only EssExTee could be so grossly incandescent > ItalianJobR53 - now with added 'MERICA and unreliability
04/17/2019 at 22:42

I could but then I have no car for however long it takes them to do that...

ItalianJobR53 - now with added 'MERICA and unreliability > If only EssExTee could be so grossly incandescent
04/17/2019 at 22:45

Can you survive without one?

If only EssExTee could be so grossly incandescent > ItalianJobR53 - now with added 'MERICA and unreliability
04/17/2019 at 22:48

Not really. I need a car and my mom just got rid of her spare that I would normally have borrowed.

ItalianJobR53 - now with added 'MERICA and unreliability > If only EssExTee could be so grossly incandescent
04/17/2019 at 23:39

Welp, that bad...

Future Heap Owner > If only EssExTee could be so grossly incandescent
04/18/2019 at 00:17

No, but i f they can be given instructions on which pins to hook up to and what they should see on each of them, then they would be able to figure out if one of the connections is broken.

What year is your 528i?

Future Heap Owner > If only EssExTee could be so grossly incandescent
04/18/2019 at 00:52

Actually if you just want to look for a broken connection, you don’t need a scope, you can do that with a multimeter. A scope/logic analyzer is overkill.

BrianGriffin thinks “reliable” is just a state of mind > If only EssExTee could be so grossly incandescent
04/18/2019 at 06:55

facw > If only EssExTee could be so grossly incandescent
04/18/2019 at 07:45

Working once implies that it’s not really dead, though finding and fixing it may still be a bitch. But if an IC were fried, it wouldn’t spring back to life. Seems more likely to be a bad ground or failed capacitor or something, though my ECE knowledge has dwindled to the point where I couldn’t really say how to track that down.

diplodicus forgot his password > If only EssExTee could be so grossly incandescent
04/18/2019 at 08:24

https://www.ebay.com/itm/Bentley-BMW-5-Series-E39-2-Vol-Service-Manual-Set-525i-528i-530i-540i/202655776690?hash=item2f2f39bfb2:g:td4AAOSwViJctwFC If you’re willing pickup a bentley, I gave mine to the guy who bought my e39 unfortunately. Vol 2 is all the electrical. You can try to google for a pdf too. But it should tell you which pins on the ecu connector correspond to which pin on the obd2 port. Once you know that, take your multimeter and set it to continuity (the Omega symbol) and test each wire as long as it doesn’t read open loop on any of the wires you will know that it’s an ecu issue.

You can try and find a used ecu with the same p/n as yours but unfortunately I think that would require using INPA to reprogram the ecu to work with all your other shit unlike the older motronic stuff.

diplodicus forgot his password > If only EssExTee could be so grossly incandescent
04/18/2019 at 08:35

Wait you’ve got a 98 right? You should have a 20pin diagnostic port in the engine bay. https://www.amazon.com/d/Automotive-Code-Readers/ASSEM%C2%AEBMW-Round-Diagnostic-Scanner-Adapter/B00VACZMRI that will adapt to the obd port standard, but I don’t think you still need a bmw specific scan tool for any data to be useful.

I found some threads on r3v about the diagnostic wiring from guys who did swaps that could help you out too.

https://www.r3vlimited.com/board/showthread.php?p=4811022

If only EssExTee could be so grossly incandescent > diplodicus forgot his password
04/18/2019 at 08:40

It’s a 2000, and the 20 pin port won’t connect either. I did mention that in my post.

“No scantool seems to be able to communicate with the car, either through the OBD2 port or the under-hood BMW diagnostic port”

Thanks for the link, I’ll peruse that when I have some time

ihm96 > If only EssExTee could be so grossly incandescent
04/18/2019 at 09:28

Just to give you some hope, when I was down and out like you after my clownshoe had its subframe tear out of the trunk floor thinking I would get stuck financing something that I didn’t have my heart in. I ended up scrapping together enough to buy a $500 corolla and I drove that through the winter while I saved to fix the Z3.

The key is buy as cheap as possible of a beater so you can save money for what you want

AMGtech - now with more recalls! > If only EssExTee could be so grossly incandescent
04/18/2019 at 09:58

Power and ground good at the port under dash? If so, then check CAN signals there. Generally a pair of wires matching in color, but one will probably have a stripe. That’s CAN high and CAN low. There may be multiple pairs of CAN wires on your port. I’m not familiar with BMW’s setup, but this is all pretty generic. Good CAN voltage should be 2.3-2.4v on one side, and 2.6-2.7v on the other. That rule is solid enough for most automotive CAN systems. Also, make sure those aren’t shorted to ground or to power. Continuity between themselves should be typically either 60 or 120 ohms depending on the specific network and where exactly you’re testing from. Check those things and let me know what you find.

Also, give a little tug to each wire individually at the back of your diagnostic connector ports. Sometimes the pins will be loose and back out when something is plugged in to them. But when unplugged they look totally normal.

Hope this helps. OBD2 is a federal standard, and CAN is an industry standard. There’s a ton of info available on both of these online if you use the right search terms. So, minus a few exceptions, overall system operation and pin positions should be easy to determine because it isn’t BMW specific. If everything else is otherwise working normally, I’d be very surprised if it’s a control module issue.

One last tip. Be gentle with meter leads. Pins can be damaged/spread from just jamming them straight into a connector. Which can also cause lots of issues and be very difficult to see sometimes.

Stuff like this is my favorite to work on. Really gets the brain working.

Good luck!

functionoverfashion > If only EssExTee could be so grossly incandescent
04/18/2019 at 09:59

I saw your rant about forums the other day. I’m curious which forums you’ve been on.

The reason I ask: I’ve been on-and-off the bimmerfest forums for a decade and all of what you posted about useless responses is true. BUT! There are of course a few genuinely helpful people and some who, I just don’t know how they have so much time on their hands, who will create incredibly helpful posts distilling the knowledge of 15 other threads down into one, looking for The Ultimate Truth on a topic. I’m thinking of ‘Bluebee’ on the E39 section of bimmerfest in particular.

While I don’t have an E39, my E46 shares a lot of mechanical stuff with them and I learned a huge amount on the E39 section, in particular from threads where Bluebee got involved. A lot of times, people like that will respond well to a DM/PM and maybe even talk to you on the phone to help you solve your issues.

Just throwing that out there. I wish I could help you. If you were in NH I’d say “go to this guy and he’ll put a sticker on it” but... yeah.

benjrblant > If only EssExTee could be so grossly incandescent
04/18/2019 at 10:15

Is there another OBD2 port such as a “diagnostic” port under the hood? Some vehicles (mine included) have a second OBD plug there. This would definitely indicate if it’s a connectivity issue with your in-cabin plug.

If only EssExTee could be so grossly incandescent > benjrblant
04/18/2019 at 10:28

As stated in the post the under-hood port doesn't work as well.

benjrblant > If only EssExTee could be so grossly incandescent
04/18/2019 at 10:33

Oh crap, I’m sorry. I glanced through it last night, thought about this and then jumped to post it early this AM. I’ll consume more coffee before posting next time.

Future Heap Owner > If only EssExTee could be so grossly incandescent
04/18/2019 at 10:43

Well, that sure does seem like a flaky connection. What year is your car?

If only EssExTee could be so grossly incandescent > Future Heap Owner
04/18/2019 at 11:45

2000

Future Heap Owner > If only EssExTee could be so grossly incandescent
04/19/2019 at 01:36

Sorry, I’ve had a real busy day with a looooong vet visit.

So based on a few different sources, it seems like that year of 528i uses a pretty bog-standard OBD-II protocol (ISO 9141-2), where you’ve got a primary signal line (which the protocol calls the “K line”) on pin 7 vs the signal ground on 5. The signal line idles high, so with the engine running, you should be able to read a 12 volt difference between pins 5 and 7.

That signal line on 7 seems to be the only required thing for the protocol... but there is an optional line on pin 15 called the “L line,” that I’ve been unable to find any concrete info on . Does your connector actually have a pin in the pin 15 hole?

Future Heap Owner > If only EssExTee could be so grossly incandescent
04/20/2019 at 02:52

That L line on pin 15 would likely be the complementary for the K line in a differential signalling scheme, so if 7 idles high, then 15 idles low, so you can’t tell the difference between that and a broken wire unless there’s activity on the CAN bus.

So much happens on the CAN bus then unless there was some weird kind of active isolation of the OBD-II port (and why would you put the cost and effort into that?), it should go high some of the time, but maybe not enough of the time to register much on a multimeter. So that’s hard to distinguish from a broken wire. Though I must say that even then, you should be able to function most of the time with only the one.

I like cars: Jim Spanfeller is one ugly motherfucker > If only EssExTee could be so grossly incandescent
04/20/2019 at 12:35

I know that I’m a few days late, but to me, the CEL going away is actually a bad sign. It means it’s intermittent and will be intrinsically harder to diagnose.

Dd you ever get the seized lugs off? I’d honestly just soak em in PB blaster and slide a long pipe over your wrench and jump.