Trans Failsafe Puzzle. Can You Unravel It?

[Edward454969]

Hello E39 geniuses.
I've been using the vast amount of information you've posted here to try and get my E39 up and going. It's currently stuck in the dreaded Trans. Failsafe Prog. But After lots of searching, testing, searching and more testing I'm coming up empty-handed. I have LOTS of experience with E36s (and currently race one with NASA, but this 5-series seems to be getting the best of me. I'd love to see if any of you can spot something I've missed, or suggest something new to try.

The car: 2002 BMW 540i. Automatic (5HP24) with 146,810 miles.

The issue: The dreaded Trans. Failsafe Prog. It has been ever since I bought it about 6 months ago. It's stuck in what I assume is 3rd gear and when you shift into reverse initially there is a large clunk.

Side note: The car also has codes showing problems with the VANOS, and there's also (what appears to be common?) coolant leakage around the valley pan (hey, I bought this car for a song, okay?). I have the intake manifold off, and a vanos rebuild kit and valley pan seal kit are on the way, so that shouldn't be a problem. But no info is bad info when it comes to trying to diagnose an issue!

Testing, 1, 2, 3....
So obviously I started with justing checking codes. I have PA Soft running on a WinXP machine. It connects to the car just fine and when I go into the EGS tab, it shows three errors:

02[002] Pressure Controller EDS2
04[004] Pressure Controller EDS4
61[097] V-Batt. Supply T. 30

What does that last one mean?????

Those codes pointed me to the EDS2 and EDS4 controllers. However, I tested resistance at the TCM connector. Below are my results along with the pin numbers on my car. (by the way, THANK YOU to whoever created this little resource years ago: http://iho-bmw.s3-website-us-west-2....ws.com/e39new/ It was invaluable to finting the right pins and testing them quickly.) Results:

(part - pins at TCM - ohms)
EDS1 - 21/28 - 6.4
EDS2 - 11/27 - 5.9/6.2
EDS3 - 11/17 - 6.4
EDS4 (EDSwk?) - 21/7 - 6.4
EDS5 - 11/6 - 6.2

According to this document (http://akpp-ivanovo.ru/wp-content/up...5HP24-diag.pdf) EDS1 should be between 5.2 and 6.8 ohms and the rest should be between 6.2 and 7.8 ohms. I checked EDS2 a second time after getting 5.9 initially and on the second try I got 6.2. So nothing seems to be massively out of spec. EDS2 looks a tiny bit fishy though.

So the computer is throwing a code for something at isn't out of spec???

I've read so many stories about how the connectors for the trans solenoids and the trans position sensor can get wet and degrade. I removed both and the pins looked totally clean and dry. Note that this issue has not gone away after the car has sat still for at least 6 months.

I've also read in at least one place that the sunroof drain can start leaking into the cabin and may have been the cause of a similar issue for at least one other forum member. To test I poured water directly into the drain and it cam out under the front fenders on both sides as it should. No evidence of water making it into the interior.

So what am I missing? I'd hate to order two $200 pressure regulators just to find that they weren't actually the issue.

One last totally blind guess/question. That coolant leak from the valley pan was dumping some coolant down the back of the engine. Could that have caused an issue? The trans position sensor plug is near there, but there are no codes thrown for that sensor.

Thanks in advance for your responses.

[msvphoto]

The last one, 61[097] is possibly the alternator or weak battery. I was getting that one when my battery was less than healthy (only a year old but bad). Swapped the battery and no more trans failsafe. Apparently the transmission control is ultra-picky about low voltage and among the first to complain. I heard bad alternators cause this most commonly but in my case it was an Autozone battery not holding charge well.

[Edward454969]

Ah, I must have looked that code up then. Because I did buy a new battery, installed it, wiped the codes and restarted. It threw the codes again so I returned the battery.

[msvphoto]

Sounds like you ruled out the battery then. I have heard failing alternator will cause this so maybe double check charge voltage.

[Chedley]

Ah, I must have looked that code up then. Because I did buy a new battery, installed it, wiped the codes and restarted. It threw the codes again so I returned the battery.

You may have bought a new but slightly discharged battery.
Anyway, can you run OBC test #7 to read the voltage of the battery with engine off, then with engine running warm ??
Report your findings.

[Edward454969]

Unfortunately I can't do the battery test with the engine on right now since the whole top of the engine is on shelves in preparation for the valley pan seal and vanos rebuild. Here's a little more info on what I've tried battery-wise. Sorry for not including it in the first post!

When I first read the transmission codes, I'm 83% sure that battery code was not there. But since I read everywhere the battery could still be the problem, I pulled the original battery out and fully charged it. Still went into limp mode. Then I pulled a known good battery out of one of my E36s. Still went into limp mode. Then I bought a new one, still went into limp mode, returned it. That battery code may have just appeared when I last pulled the codes as the car has sat for six months without running for any extended period of time. (I've pulled codes multiple times after trying different remedies.)

So I'm fairly confident the battery isn't the issue, but I will definitely do your test once I can run the car. Thank you for the suggestions!

So why would the computer report faulty EDS2 and EDS4 when they check out within spec? Could that be a bad egs/tcm?

[msvphoto]

Unfortunately I can't do the battery test with the engine on right now since the whole top of the engine is on shelves in preparation for the valley pan seal and vanos rebuild. Here's a little more info on what I've tried battery-wise. Sorry for not including it in the first post!

When I first read the transmission codes, I'm 83% sure that battery code was not there. But since I read everywhere the battery could still be the problem, I pulled the original battery out and fully charged it. Still went into limp mode. Then I pulled a known good battery out of one of my E36s. Still went into limp mode. Then I bought a new one, still went into limp mode, returned it. That battery code may have just appeared when I last pulled the codes as the car has sat for six months without running for any extended period of time. (I've pulled codes multiple times after trying different remedies.)

So I'm fairly confident the battery isn't the issue, but I will definitely do your test once I can run the car. Thank you for the suggestions!

So why would the computer report faulty EDS2 and EDS4 when they check out within spec? Could that be a bad egs/tcm?

If you're that far in and doing vanos rebuild you might want to go the rest of the way and get new guides in at the same time. Mine went (U guide lost all plastic) with no warning at 175k miles and I am just now getting my car back on the road.

As far as the EDS2 and EDS4, I can't help much, but there have been a lot of posts about the low voltage error code being the first indication of a failing alternator. I suppose it is possible that in that low voltage detected state other things being monitored by the TCM could be false errors if set at the same time. Assuming the car shifts well and smoothly when not in failsafe you might be okay. After the TCG job I am wrapping up the transmission is my next biggest fear, but at least it is just one big chunk that can be swapped out instead of a bazillion little pieces.

Good luck and I wish you success.

[Edward454969]

Good suggestion on replacing the guides while I'm in there. I just ordered the parts. Thanks for the reminder.

Anybody else think this is a TCM issue rather than a transmission issue? I wish I knew somebody with the same car and transmission. Swapping TCM modules would quickly and easily rule that out. Anybody local (Maryland) have a spare?

[Chedley]

Yes, it could be a TCM (Transmission Control Module) issue.

But then again, I have seen so many modules in the E39 -including the TCM- acting erratically and reporting sporadic weird errors when the battery's volatge is fluctuating weak. So, before doing any other repairs that could actually aggravate your problems, I would make sure the battery is good and fully charged, and the problem is reproducible.

[Edward454969]

Copy That. I guess I'll finish the engine refresh and then test the battery with the car running. I'll report back once I have that going. Thanks again everyone. And please feel free to let me know if this sounds like another obvious issue I'm missing.

[mattmar1]

one could always remove the alternator and take it to a reputable shop to be tested to prove/eliminate it.

[jicaino]

I had a failing VR frying a EGS and it wasn't fun at all! But it first disrupts the data lines in a weird way, so you may want to verify your battery and alternator, AND voltage regulator. Also when I bought the car it had been sitting for some time and the tranny wasn't happy, as I sarted using the car more and more, I topped off the fluid, removed some fluid and added fresh one, eventually I did a fluid and filter service (No power flush!!!!) and new battery and the car felt like brand new.

[Edward454969]

Well the saga continues. I finished refreshing the engine and VANOS system. It purrs like a kitten now!

However, I did more troubleshooting and couldn't find a culprit for the EDS2 and EDS4 errors that are putting the car into trans failsafe. So I said screw it, bought a known working used transmission, and swapped them out thinking it may just be a mechanical issue. After the new trans was in I cleared the codes with my PA Soft tool and drove around again. It threw the EDS4 error again almost immediately and went back to limp mode. The EDS2 error also reappears, but it doesn't seem to be immediately thrown like the EDS4 error. So it appears the issue is not the transmission itself.

On to other theories: My traction control light is always on. My ABS lights seem to come and go. I hadn't noticed this before. So I started to think it's something with the ABS system, not even the transmission. I checked the errors on the ABS and ZKE with PA Soft and found more errors that seem to point to something in the ABS system. I'll attach photos of the errors below.

I read that the front right wheel speed sensor has some effect on the EDS4 solenoid in the transmission. So I swapped the left and right wheel speed sensors. Still no good.

More to come... Felt like it was getting a little long for one post.

[Edward454969]

After seeing those errors in PA Soft I thought I needed a more in-depth diagnostic tool to get more info. I ordered a good K+DCAN cord and got INPA up and running on my shop computer. I could see the EDS4 and EDS2 errors in the EGS. (Yay!). However, when I went to view the ABS computer it couldn't connect. Again, I'll attach photos of some of what I was viewing in INPA. I could see all the live data on the engine and Trans, so the program seemed to be working fine.

Maybe I'll try disconnecting the battery and reconnecting. Don't know what that would do, but it's strange that PA Soft appeared to be communicating with the ABS module to pull codes and INPA can't. I haven't tried PA Soft again since I got INPA up and running. Maybe I'll try and see if it can still get the ABS codes.

But regardless, does it sound like I'm on the right path by shifting attention to ABS or am I being wacky? As always, thanks in advance for the feedback.

[jsloden]

I had similar issues about a year ago in my wagon, albeit it was a 525i with the six cylinder and the 5hp19. I purchased the car cheap with the trans in failsafe mode. I literally tried everything. I could clear the codes and the car would drive perfectly fine but after a couple of key cycles the trans failsafe message would return and put the car into limp mode. My problem ended up being the trans computer. I purchased one cheap from the pull a part and replaced it. Never had another problem out of it. I had read it was a sort of common problem on the six cylinder cars, not sure about the v8's though. Might be worth a try.

[Edward454969]

Hmmmm. Interesting. I've thought about that before, but aren't the trans computers coded to a VIN? Wouldn't I have to have it recoded? Or can I do that through INPA?

I like that thought though.

[jsloden]

I had thought the same thing but my indy informed me that the trans computers are interchangeable as long as they are hooked up to the correct transmissions, at least on the e39 cars. I actually got my replacement out of e46 330i, checked the part numbers with my old one, put it in and I was good to go.

[Edward454969]

No way! Okay I'll have to try this next. You're the man.

I actually originally wanted to change the trans computer, but then thought I read they were coded to VIN so I went with what I thought was the cheaper dart throw: A used transmission. Looks like I was misinformed.

[jsloden]

I can tell you for sure that they are NOT coded on the e39 and e46 cars with the 5hp19 transmissions. I would assume that they are also NOT coded on the v8 cars with the 5hp24 but do not know for sure.

[rdl]

I'd speculate that if you do change the EGS (transmission module) you ought to have the software version checked. (which is different from coding) The transmission has to "know" the engine it's mated to and shift accordingly; the transmission and engine modules continuously "talk" to one another to co-ordinate shift points, engine braking, etc. Transmissions programmed for an M62 vs M62-TU will likely have different decision maps embedded in the program. Probably not different enough to cause harm, but perhaps enough that you wouldn't get best performance, response or fuel economy. I'm happy to concede that I don't know if this is an issue, just thinking of possibilities.

You could likely find help on checking the program version of current and new EGS, as well as a procedure for a DIY reflash if that seems necessary on this forum.
https://www.bimmerforums.com/forum/f...ostic-Software

[Edward454969]

Just went to my local junk yard in search of an EGS. Three E39s there but none had the correct module. I see one with the exact same part numbers on eBay. But I'd like to confirm some logic with you guys before I toss more cash at the dart board.

Is it possible for the ABS and steering angle sensor errors to be tied to the EGS being bad? Or if an error in one of the systems is inflicting errors on the other would it be more likely for the ABS system to be the culprit with its many different error codes? Or is it possible the EGS errors and ABS errors are unrelated? Again, I read that the front right wheel speed sensor influences the EDS4 solenoid. Seems like the two systems communicate fairly closely.

[Chedley]

So, INPA cannot communicate with the ABS module, but does communicate with all the other modules (Emgine, EGS, IHKA,..etc..), yes ?
If so, I'd say you have a bad defective ABS. Repair it. It is often a simple wiring connection in the ABS that gets fried with the constant heat.

The EGS errors can be related to that bad ABS for the same cause : bad electric connection.
I assume you did make sure you have a good fully charged battery, and alternator ? yes..??

[jsloden]

I would think that the the reason for the abs codes would be the abs module as they're a common failure point. All I know is like a I said earlier, If you get the same part number tcm then it should work, I can confirm this in the six cylinder cars only though. The e46 and e39 cars with the m54 engines pretty much all used the 5hp19 transmissions and tcm's. I have a 525i wagon and it had the same tcm as a 330i sedan. As long as you get the same part number I believe you should be fine. You might want to check for 740i and il cars. I believe they have the same transmission as you.

[Edward454969]

So, INPA cannot communicate with the ABS module, but does communicate with all the other modules (Emgine, EGS, IHKA,..etc..), yes ?
If so, I'd say you have a bad defective ABS. Repair it. It is often a simple wiring connection in the ABS that gets fried with the constant heat.

The EGS errors can be related to that bad ABS for the same cause : bad electric connection.
I assume you did make sure you have a good fully charged battery, and alternator ? yes..??

Okay so a little update. My K+DCAN cable has a switch. I assume this is the fabled 7/8 pin switch. The instructions that came with it said to keep the switch to the left for cars made before 2007 and to the right for cars made in 2007 and later. My car is a 2002 so I never moved it from the left position. However, last night I flipped the switch. I got a couple warnings about communication but it did connect me to the ABS and steering angle modules and I could see errors and live data. So that turned out to be a diagnostic tool setting, maybe not a failing module. But I guess it's still possible. There were errors. Photos attached.

I don't speak german so I'm going to have to do some hunting to figure out what those errors mean though.

And yes, I have checked the battery and have switched it out many times. It did not seem to have an effect.

jsloden, I think what you're suggesting is worth a try. When your TCM was causing issues, did you have traction control and ABS lights on?

[Edward454969]

One strange thing I noticed in the live data: It always shows my "cross acceleration" pegged at 23.4 m/sec sqd. This photo was taken when I was sitting still. That shouldn't be like that, right?

By moving the steering wheel, the steering angle would change, but if I remember right the rotation rate always stayed the same at 67.1 as pictured. Does this raise any red flags? It at least does not seem accurate.