Advice Please: '05 4.8is with Trans Fail Safe mode error, have only 50k miles
 

Hello,

I'm original owner driving my 2005 X5 4.8is LeMans Blue off the dealer showroom floor in 2005 with only 11 miles on it. Have had it ever since and only put 50K miles on it, always garaged, all service records. It's my baby and now I have a "trans fail safe mode" error. I read some threads here about this issue, but would like to get some members advice on what route I should take going forward for repairs based on what the issue might be.

I've taken it to my repair shop for over 12 years, originally a Dinan shop, but since has changed owners and former BMW mechanics now run the business. They are very trustworthy and know all about BMWs, but they would send out tranny's for rebuilds. They gave me cost options to decide:

1. Replace solenoid kit only and see if error does not return, if all good, cost 1800.00
2. Go directly to a tranny rebuild (ZF tranny) cost 6300.00 (includes solenoid kit)
3. If I do the solenoid kit only and error returns, may have to rebuild tranny, cost 1800 + 6300 = 8100

I love this car, been my daily driver for work, personal trips and just a great ride. Would hate to lose it, but I'm at a crossroads with repair cost vs age of vehicle. Still in great condition, has custom interior and all top of line options offered for 05 model. I have pics of my baby when I got it 16 years ago, except for some normal wear to interior, in great condition.

My 4.8is Pics

Would appreciate any advice on the path to choose.

Thanks,
Jeff

My 04 4.4i has less than 42k miles on it. About two years ago it started getting Trans Fail Safe error messages only on cold mornings (less than 50 F). I had noticed a fluid stain under the transmission. It turned out that the fluid was low from a leak in the mechatronic sleeve. The o-rings on the old sleeve had flattened, causing the leak. My mechanic changed the sleeve and we drained and filled the fluid three times. Hope it's that simple for you.

My mechanic said we probably didn't have to do the three drain and fills because the fluid looked pristine. However, I'm glad we did. I was getting some harsh shifts from first to second gear, probably because of the low fluid. Those went away after the second drain and fill.

I was also having some electrical gremlins around the same time which complicated diagnosing both problems. We also replaced the alternator which made the gremlins go away.

Gorgeous! I don't think I've ever see exhaust tips THAT clean :mmm:. You seem to have lost your running boards though :)

I have had a trans failsafe error (not sure of exact wording of the message) on my 3.0i when the alternator was flaking out a little (and the transmission was just fine, and still is). Your 4.8 has a ZF AT vs. my 3.0 has the GM, but I'd at least consider an electrical issue causing the message before diving in on AT work.

Same here on my M54/GM 5L40-E. Alternator was flakey and Trans Fail Safe message. Check your voltages before dropping thousands of dollars. I sure you have plenty of life left at 50K miles.

Update: '05 4.8is with Trans Fail Safe mode error, have only 50k miles
 

I appreciate all the input about my problem, I will pass on to my mechanic about voltage/alternator issues...Maybe that factors into it. Meanwhile, I sent my mechanic an email that I read some threads on this forum for the error I'm getting....He replied back with a very transparent and detailed description about my issue and how BMW transmissions rely heavily on sensors, fault codes for diagnostics and so much more...If your interested in reading his reply below it might be good reference for others and may just convince me to at least try the Solenoid kit option for my problem.

Here is his sincere and informative response...Thanks.

>>>>>>>
We understand the situation you’re in, my partner and I have been working in this industry (and most of our careers, together) for a combined 30 years… it’s a tough spot to be in for the vehicle owner and we have no problem with unturning as many stones as necessary.

I’d like to preface this by saying that when it comes to automatic transmission repair on BMW’s, there are very very little parts available that are internal to the transmission. Things like clutch packs, friction rings, drums, actuators, sensors etc. are not available for ordering.

You essentially have access to some seals, fluid, gaskets, some snap rings and that’s about it… there is of course the control unit as well, but this is a whole different topic of conversation when it comes to transmission repair.

You have to consider that the transmission control unit (which I will refer to as TCU henceforth) is constantly monitoring the operation of the transmission. This means voltages, grounds, signal wiring, clutch actuation, pump pressure, valve block usage (you get the point.)… One major benefit to this is that from a diagnostic standpoint, there’s quite a bit of sophistication by the way of fault codes. Understanding what a fault code is trying to tell us is “Diagnosis 101” when it comes to professional automotive repair…

..for example, a short circuited supply wire to the TCU would result in several fault codes which would be displayed in the test equipment as:
Terminal 30 supply, Transmission control Open circuit Voltage supply, transmission control, MISSING.

The operator of the vehicle would simply see: "Trans Failsafe PROG"

This is why when searching on Google or forums for rudimentary terminology for these kinds of failures can be dangerous… what seems like a simple message which should be explicable by maybe one or two different issues is a total distortion of reality – the light comes on for potentially 250 different reasons! It’s our job to utilize fault-driven diagnosis procedures to narrow these 250 reasons down to 1.

The fault code exhibited in your vehicle is one and only one code in the TCU:
4F95 Ratio Monitoring, Clutch B-E

So lets dissect what this fault code means:

- 4F95 is hexadecimal information and it’s for engineering purposes to identify the fault.
- Ratio monitoring means that the TCU is monitoring the ratio of input vs output speed and sees an issue.
- Clutch B-E is the physical clutch pack that is exhibiting a problem.
So to put this in layman’s terms if I took the position of the TCU, I’d be telling you: “I see a problem with the clutch pack B-E – it seems like based on the input speed, the output speed should be higher (or lower?)… this means I must be slipping. Let’s set a light to warn the driver and default the transmission to 3rd or 5th gear so they can get to the nearest repair facility.”

This rules out a couple things immediately:
- WIRING: If wiring is bad, you would get faults for intermittent “opens” or “shorts”.. not physical plausibility faults.
- SENSOR: If sensors are reporting incorrect signals, the TCU has diagnosis routines it runs to check these and will display “sensor range” faults.. meaning that the sensor is transmitting an implausible signal given the vehicle’s current scenario it’s being driven under… not to mention, all the sensors are integral to the transmission and would require overhaul to access and replace anyway…

No, this is definitely the TCU trying to illustrate to us that something is causing the clutches to slip – so why would they? A clutch is meant to slip between gear changes by design so the user of the vehicle doesn’t feel a harsh transition when going from first to second, second to third, third to first, first to fourth and so on… This is accomplished by the valvebody, the drums, the friction plates, torque convert, fluid and pressure.

The fluid level was checked on your transmission and is correct type/level.

So, if it’s a valvebody, this requires teardown, labor for replacement, programming, fluid, gaskets etc.. this repair would be very expensive – in fact, near the price of the rebuild and *DOES NOT GUARANTEE INTEGRITY OF CLUTCH PACKS*.. meaning a variable is left twisting in the wind which is not good from a major repair standpoint… the savings would be minimal and wouldn’t be a guarantee from us. There’s just not enough evidence to show that this is the definite problem.

If it’s a drum/clutch pack, this requires teardown and rebuilding of the transmission.

If it’s a pump, you’d be having faults for all the clutches not just one. You’d also have a lot more faults than just 1 – you’d have faults showing that your pump pressure is inadequate as the sensors inside the valvebody would pickup that there’s a “Main pressure, plausibility” fault… all situations that you’re not experiencing. Also, if it’s a pump it requires teardown and rebuilding of the transmission..

What about a torque converter..?? Well, let’s assume this might be the issue. All-in, this would possibly save you $2,000, but doesn’t verify integrity of clutch packs internal to the transmission nor does it ensure integrity of valving inside the valvebody. So it’s a heck of a lot of expense, leaves many stones unturned and is just a guess. Also, the fault codes and symptoms don’t justify failure. When torque converters fail, you typically get a non-rhythmic slipping sensation when maintaining speeds around 50-65mph, you might get noise, you may also get a really fast idle and the car will jump off the line if a torque converter is “locked up”… Also, the TCU can monitor torque converter slip and will set a fault code for it specifically in my experience – another benefit to having computers watching how things are turning!

If it’s a TCU, well that *IS* a valvebody! That’s right, the TCU is part of the valvebody on this model.. it’s a computer submerged in transmission oil and it referred to as a “Mechatronics” by the manufacturer:

This is *EXTREMELY* expensive and does not guarantee integrity of clutch packs… it requires programming as well. Don’t get me wrong, I have replaced these in the past but for much much different scenarios, not ones concerning slipping perse, but usually signal faults and/or voltage faults or software glitches… think faults that would describe intermittent contact or solder joints breaking and so on…

So we’re left with a clogged solenoid for clutch B-E activation or the physical clutch B and clutch E packs. This is what you were quoted.

As I explained on the phone, if this transmission had 100k+ miles on it we wouldn’t even consider the solenoid pack because we’d want to get all new parts inside of this case to ensure it’s something that will last for the user. Also, from a business standpoint we have to be able to warranty this repair for 2 years unlimited mileage and we just wouldn’t be comfortable replacing a singular component inside a transmission that has high mileage knowing there’s a good chance in 10, 20 or 30 thousand miles it could burn up a clutch pack and then we’re doing a full rebuild anyway.

However, your situation is unique… your vehicle is very low miles and for a clutch pack to be burnt up seems very unlikely. There’s a really good chance it’s just a stuck solenoid, or a solenoid that engages improperly. The simple truth is we just don’t know and it’s taking a chance. If we knew that it was a 100% thing, we would’ve explained that but we’re trying to be as transparent as possible and explain that we aren’t 100% sure and it certainly COULD be a worn clutch system inside the transmission.

Remember there’s several different variants of transmission on these E53’s and your specific one is the rarest. It’s the actual 6 speed from ZF. Most of them are the 5 speeds and they only started the 6 speeds from like 2005-2006 in the E53 chassis… this transmission is what they put in the 5 series, 6 series and 7 series of that generation.

I know this was long and I hope it answers some questions. We appreciate your business and know that we have no issues being as transparent as possible throughout this process.
>>>>>>>

I have a different gearbox than you so I can't really help but I am hoping our resident AT guru from the UK @rrphil will chime in and give his opinion.

I read your response from your mechanic as: we have no idea other than the 1 code you have but we can try a few things but no promises.

First, very nice looking X5. Unfortunate the trans is acting up. Second, your shop is great. Very upfront. Nobody knows these transmissions in any sort of "expert" fashion, with the exception of a handful, one being Phil as Overboost mentioned. He is amazing.

Funny, I am writing this at 3:30AM because I am replacing the transmission in our E70 (a variant of the same trans that is in your 4.8), also because of an E clutch fault (4F89 - 3/4 Gear Ratio Monitoring). It was determined through trial and error (only way to diagnose these without being one of the said experts). Had the valve body rebuilt with new solenoids, seals, etc. Tried fluid 4 times. No luck. Guys who rebuilt my valve body did warn me that it is likely an E clutch bushing/bearing failure before doing the work. Great service. So, end result, replacing our 166000 mile transmission with an 80000 mile unit. It is NOT a fun job, but that is mostly due to this truck being a diesel.

Anyway, if I were you, I would do (or have your shop do) a drain/flush with Valvoline Maxlife Multi Vehicle ATF. It's not recommended, and your shop will probably balk, but the fluid is MUCH thicker than the stuff spec'd by ZF/BMW for the transmission. If you are lucky, it will allow whatever in the trans is not building/holding pressure to do so again. It is a cheap attempt, especially compared to your other options and so you really don't have much to lose. $200-300 at a shop. The fluid itself is only about $50.

If that doesn't work, I'd continue down the path of least resistance. Full valve body rebuild with solenoids and Sonnax Zip Kit. Not just the solenoids. If that doesn't work... skip the rebuild and buy as low a mileage unit as you can find. Transfer your rebuilt valve body and mechatronics (TCU) to the replacement transmission. At least then, you will have a low-mileage refreshed trans. That's the exact course of action we took with our 6HP.

Good luck. Hoping to have ours back on the road in the next few weeks. Just got the new trans installed a half hour ago, but still have lots of other "while I'm in there" stuff and then of course putting all the diesel emissions stuff back in the truck. Think 10lbs of "stuff" in a 5lb sack.

Here is a great source of information for ZF transmissions and specifically the 6hp. https://axleaddict.com/auto-repair/Z...E-Clutch-Fault

Since my mechanic said I can take as much time as reasonable to figure this out, maybe the AT guru you mentioned might chime in at some point. I believe my mechanic is looking at this based on all the data he sees and what he has experienced with other customers.

Every time I brought my X5 into his shop for service he always told me everything I should know so I could decide how to proceed, rather than telling me this is what I can do, take it or leave it.

Thanks for your input.

I'll mention your suggestion to my mechanic, in the past I've found him open to trying other options rather than pushback.

Thanks for the suggestion.