FIXED - P1747, P0721, "TRANS. FAILSAFE PROG" Warning, and Limp Mode (My Experience)

[BLAUE39]

Hi e39 folks! I have been lurking since I bought my 5-series four years ago. Very grateful for this forum as it has helped me with many fixes for my car. Thank you! Until today, I have not posted since there wasn't really anything I could contribute...

I have an automatic 2003 530i with 177K miles. The trifecta of lights hit me in early 2017 (always intermittent, 50% on and 50% off), never fixed it. Just a couple weeks ago, the transmission shifted from 1st to 2nd (or was it 2nd to 3rd)...hard! Dash came up with the Transmission Fail Safe Mode warning and SES light right away. I turned off the car the first time this happened, accelerated, and another huge JOLT, it did it again. Turned off the car again, and this time the transmission stayed in limp mode.... crud!

Limped home. I got an Innova scan tool and pulled the P codes: P1747 (can-bus monitoring), P0721(output speed shaft speed sensor circuit range/performance), thus started the web search for solutions- primarily looking at the P1747 code.

Full list of symptoms at this point:

1. Now trans is stuck in 3rd or 4th...it felt more like 4th gear.

2. No Speedo

3. No Trip meter

4. No MPG

5. Didn't try Cruise Contrl.

6. Very poor acceleration.

7. Once over 40mph, car is smooth and good.

8. Reverse works fine.

Here is the troubleshooting I went through:

1. Checked wheel speed sensors - couldn't figure out how to get the diode readings from my multi-meter...

2. Disconnected battery to clear the codes - couldn't clear the P codes.

3. Used OBDII scanner to clear codes - couldn't clear the P codes.

4. Checked transmission fluid level - level fine.

5. Looked for loose trans cables - all in tact.

6. Disconnected and re- attached the front and rear cable connectors on the trans - didn't help.

I couldn't find too much on the P0721 code (output speed shaft speed sensor circuit range/performance), so I put that one off to later. Since I saw that P1747 (can-bus monitoring) and trifecta of lights, were often caused by a failing ABS module, I sent in my ABS module to module masters. I chose these guys since they have a 5 yr warranty, would return my money in case the module is unfixable, and I saw a few other success stories with them. More money than others, but risk was lower. $300 fee for the fix, plus shipping both ways "overnight" fedex (<-- not a fan of this service as they don't ship on Saturdays), brought the total to $345. A painful week and a half later, after missing then chasing the fedex delivery truck...

RESULTS:

1. TRIFECTA GONE!

2. Speedo back

3. Trip meter back

4. MPG back

5. Cruise control works

6. Reverse works still of course.

7. STILL NO ACCELL and trans in limp mode.

8. Same codes still presents with my code reader and SES Light still on.

Dang it all. I am at a loss. Several times thought about buying a new car.... but quickly caught myself.

Next clear thought was to get the car to a shop that could read the manufacturer codes and clear them. So I limped the car to a body shop that I used to fix my other car, they have a ETHOS Tech Snap-on scan tool. Codes read:

1. 128 - CAN-Bus Monitoring

2. 32 - Speed Signal N - Ab

3. 130 - CAN: Timeout ABS/ASC/DSC

4. 59 - Stall Monitoring

Keep in mind that some of the codes could be past events that are no longer "active". They scanned and cleared all these codes for free. I am very pleased with this shop.

.... Not expecting much from clearing the codes, I got in the car, cranked the engine. No SES dash light on. Backed up, fine. Put her in drive.... rolled on the power. FIRST gear was engaged.. I'm a little surprised. Then shifted seamlessly to SECOND gear, I'm getting happier. Drove out of the parking lot and onto the road, got up to 45mph, smooth like butter. I was ecstatically speechless the whole drive home. I did hold my breathe the next few drives, but all is well with the car now. I have driven for 300 miles since the codes were cleared.

Recap Notes:

ABS module repair (AND clearing codes with legitimate scan tool) fixed my P1747, P0721, "TRANS. FAILSAFE PROG" Warning, and Trans in Limp Mode!

Looking into the P1747 fix first was a good thing to do instead of chasing P0721 (wasting time and money).

Thank you! --- I hope that was not too painful to read thru, but hope this experience may help someone with these codes that I had.

[BavarianE31]

Glad it worked out for you. Now time to buy a scan tool that allows you to clear codes (there's BMW software floating around that you can launch on your laptop or maybe even phone).

Also, BBA Reman offers ABS module repair for $90; they are the Go-To guys for ABS repair on the forums. Fast and awesome service with a lifetime warranty. Now you know!

[geargrinder]

WTF happened here?

huh. weird. OP went away and came back.

[BLAUE39]

I thought the same thing geargrinder. I made an edit to correct my poor spelling, and the OP vanished!... and now it is back. Odd.

[msvphoto]

Glad it worked out for you. Now time to buy a scan tool that allows you to clear codes (there's BMW software floating around that you can launch on your laptop or maybe even phone).

Also, BBA Reman offers ABS module repair for $90; they are the Go-To guys for ABS repair on the forums. Fast and awesome service with a lifetime warranty. Now you know!

BBA Reman is not lifetime warranty if they repair the module for a used car dealership and you purchase the car from said dealership. I have one they fixed that lasted only around 8 or 9 months, but because I was not their customer, no warranty. Suffice to say I am not super thrilled with them at the moment. Both because the repair didn't hold for very long, and because they wouldn't honor their warranty.

[f355spider]

BBA Reman is not lifetime warranty if they repair the module for a used car dealership and you purchase the car from said dealership. I have one they fixed that lasted only around 8 or 9 months, but because I was not their customer, no warranty. Suffice to say I am not super thrilled with them at the moment. Both because the repair didn't hold for very long, and because they wouldn't honor their warranty.

Actually it is a lifetime warranty, but what you are describing is a "non transferable" warranty. In other words, the warranty is only valid to the original purchaser. A little restrictive, but not unheard of.

[geargrinder]

Actually it is a lifetime warranty, but what you are describing is a "non transferable" warranty. In other words, the warranty is only valid to the original purchaser. A little restrictive, but not unheard of.

Yep. In fact MOST 'lifetime' warranties are non-transferrable. DEFINITELY highly common in the car world. Bilstein, Koni, etc. etc. Often they use the term "Limited Lifetime" but then the small print explains that the limitation pertains to the transferability.

BBA Reman has an excellent rep as a rule, shame that unit failed, but you can kind of understand their position.

Its one thing to say "we'll guarantee all our direct customers for as long as they own the unit / car..." vs "we'll continue to repair any unit we have ever had in before until the end of time no matter who finds it". You could easily have a business and be willing to do the first and not be able to afford the second. Which is why virtually nobody actually offers the second.

and because they wouldn't honor their warranty.

No. That's wrong. There is no evidence they won't honor the warranty. You just want the warranty to grant terms that it does not.

This kind of vendor-ripping for limited lifetime warranty by the way is not an uncommon "wahhh" in car world sadly... "how come nobody told me the warranty that they gave the previous owner wasn't transferrable, these guys are teh sucks!"
I think its a bit bogus. They could offer a 6-month or 1yr or whatever warranty they wanted, in fact what they offer is pretty generous. You're just looking to hold them to something that isn't what they warranted to the original purchaser.

Now - going bad after 8-9 months, yes, that does sound like crappy luck, and one would hope maybe they'd grant an exception to that on general principle, IF you had the documentation of the original purchaser...

The other route that some vendors might even suggest is "yes we'd be happy to warranty that but can you please work to get the original purchaser to send it in" which can work fine as long as said purchaser is reachable and friendly. Not legal for say, Bilstein/Koni warranties because they explicitly say "as long as you OWN the car" so you'd have to scam to do that, but I imagine BBA-Reman would honor a module warranty if you can get the guys who paid them to give you some help.

[msvphoto]

Bad wording on my part perhaps. Good to know they BBA is a good vendor. I do still need to get the module rebuilt. I had thought I would maybe try a different rebuilder and/or module, but with the good endorsements for BBA, maybe I'll give them a shot at fixing this sucker again.

I thought about opening it up and having a crack at it myself, but after seeing some pics of the guts and realizing we're talking about soldering wires the size of hair to a thick film ceramic "circuit board" I had doubts about success. (I have done SMD rework since the 1980s when I was first trained by Sony when I worked for them as a tech.)

I do still find it a bit unusual not to extend a warranty on a part, or rebuild of a part, from a repair shop/dealership to the customer/end user. Pretty sure Koni & Bilstein warranty extends to the car owner if installed by a repair shop/dealership. That is how Arnott does their lifetime warranty. (There were a lot of upset allroad owners that didn't understand how Arnott's lifetime warranty works.) That is how I did warranty when I ran the largest Blaupunkt repair station in the Western US back in the 1980s. It didn't end with the dealership or repair shop, it extended to the owner of the car.

I'm not exactly going "wahhh" since I am the first owner of the car that the module repair was done for (module rebuild was done for the dealership during prep for sale and I bought the car). Technically there was no transfer. The dealership owner is a friend and I could have routed the repairs back through him but felt that wasn't being honest with BBA, so I called them and explained the situation and was declined. I do have documentation from the dealership. If I were managing the BBA shop (and I have managed many repair shops over the years) I would have extended some kind of good will gesture to the customer in this case. BBA took down information (invoice number) and looked things up on their system so having my friend that owns the dealership run it through now is probably not an option since I was truthful up front with them.

My symptom is just no DSC and a high pressure pump fault when I scan with INPA. In talking with BBA they were pretty confident the module is bad again. Thankfully no Transmission Failsafe from it (yet). I have ignored it for several months now, but it is rising on my to do list.

[BavarianE31]

That is unfortunate, but you can always go to Module Masters like the OP, pay $300 for the repair and get a 5 year warranty instead.... Seriously though, BBA Reman has a good reputation around here. It is a shame that they didn't extend their warranty to you, but that's within their right. It may be difficult to go with another shop (excluding the extra expense) because the unit has already been opened up and most places are skeptical about repairing previously repaired units (they usually will not give you a warranty). I'd send it back to them since they are going to be the cheapest option. They have to accept it since the previous repair was done by them and maybe they can learn a thing or two about their repair quality as well.

[geargrinder]

With luck maybe they'll have a change of heart once the part is in hand and give a break on it.... vs just "some Joe calling up" where they can't be sure the unit really was one they worked on etc.

[ELA]

saved.

[Kirk Anderson]

That is unfortunate, but you can always go to Module Masters like the OP, pay $300 for the repair and get a 5 year warranty instead.... Seriously though, BBA Reman has a good reputation around here.

Three and a half years later: BBA Reman (which was about a mile from my house) was seized by law enforcement last year and is now out of business. A mechanic near me said he had stopped using them a couple years before due to modules coming back bad. I was one of the lucky ones who found his module in their stock when the local sheriff opened it up for us one morning. No idea what sort of shenanigans led to this.