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Discussion Starter · #1 ·
I recently had my mechanic replace the transmission in my 2001 540iT Sport Wagon based on the diagnosis from Concord BMW. When it was installed, the car dropped into the Transmission Failsafe Program mode and displayed transmission code 15: Pressure actuator failure. This is also generic OBD II code 1748: Manufacturer Transmission Control Unit Malfunction and/or Transmission Control Unit Self Test Failure.
Has anyone experienced this problem? If so, what was the diagnosis?

My mechanic doesn't have the big BMW test set to fully diagnose this issue so I've made an appointment to take the car to Concord BMW for diagnosis.

I also had the transmission control module replaced and reprogrammed. Does anyone know if the transmission failsafe program cuts out a lot of the transmission control module functions?

First off, the shift selector indicator on the dashboard is disabled. According to the service manual, the LEDs are enabled through the TCM. Also, the shift lock solenoid is not operating. I can put the car in any gear without having to depress the brake. The pathway for this circuit also travels through the TCM. Unfortunately I do not remember if those two items worked before I had the transmission replaced.
The sport mode is unavailable and no indicator lights change when I tap the shifter to the left.
Additionally, the parking control assist does not activate when the vehicle is placed in R (possibly indicating an electrical problem vice a hydraulic/mechanical problem with the transmission).

I am trying to avoid another R/R of the transmission and was wondering if it could be the computer interface inside the transmission? If so, can that be replaced? I have verified continuity between the TCM and transmission connector and a visual inspection of the connector pins does not indicate any damage/missing pins.

Even though the car is sluggish from the start (because it is stuck in 4th gear), it drives great.

The last time I had the transmission diagnosed by the dealership, 20 minutes later they said, "We couldn't see anything wrong specifically, BUT you need to replace the transmission." $6000.00 later, I now have a working transmission but I am still having issues. Any input to help isolate the issue BEFORE I take it back to the dealership for their input would be greatly appreciated.

2001 BMW 540iT Sprot Wagon w/ Steptronic 5 speed
ZF transmission part# 5HP24A
:dunno:
 

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Transmission issues

My 2001 540 4-dr. sedan just had the 'failsafe transmission prog' come up on my dash. I took it in and it was diagnosed with a burnt transmission. The oil had been burnt completely.
They said I need a new transmission at a cost of $7,500.
This is absurd for a car that has been maintained exclusively by the dealer since I purchased it brand new. It has 180,000 km on it which is not excessive for an engine of this nature. I'm an executive and drive the car around a big city in normal traffic conditions.
This should never have occured. They are now scrambling to reach a compromise solution.
 

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Discussion Starter · #5 ·
Update on the transmission issue, it turned out the "new" transmission was the wrong part. It was the correct ZF part number (5HP24), but it was the wrong BMW part number (orgionally out of a 1998, I have a 2001). The problems were because the transmission control module couldn't talk to the new transmission. It took 8 weeks and two trips to the dealership to figure this out. The money was bad enough but not having the car for a couple of months was really frustrating.

But, with the correct part number the car runs great. Taking her down to San Diego this weekend :p
 

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How do you read the transmission error codes? I have the Pieke tool and I was testing my transmission shifts and it went into failsafe but I couldn't get any codes out of the Pieke (just got the "---")
I had the same issue came on twice within minutes of each other and then nothing ... car now drives fine .. I was on a very steep incline hill when the trans failsafe came on. Just weird?

btw, didn't you just complete a tranny fluid change? Is the car running and did the light come on again?

what i have read .. it can be the battery ... or altnerator ..
 

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In the morning and when the car is really cold it shifts crappy. It either bangs into gear, looses power while turning and accelerating. When I shift manually it seems to act a lot better. When the car is warmed up it seems to act a lot better.

When I took it out at lunch (cold) I was doing some testing. I turned off the DSC and did a hard launch in automatic - sport mode. It felt like a slipping clutch going into gears and then going into 4th the Transmission Failsafe light came on. I was kind or relieved to at least know I wasn't crazy and would have some codes to work with.

I got home. Turned the engine off. Inserted the Pieke tool. Then turned the key on. Then pressed Go. No codes "--". Nothing.

Turned the car on. No Transmission Failsafe. Drove around. Car drove perfectly fine. Tried to repeat the transmission failsafe and couldn't do it. Very frustrating!

Now I have been getting some weird electrical things lately. I had 3 of my 4 new Angel Eye rings light up and the 4th would come on later. Re wired the whole thing and didn't help. Bumped up the fuse and that helped 100%.

Then the brand new battery dies on me 2 days ago. Ordered the FSU for replacement and charged it over night but no problems.

Then I started the car after work yesterday and the flashers and the dome light came on - on their own.

So it could be alternator, new battery is bad, VW MAF unit doesn't work I just put in, did something wrong when doing the tranny fluid, etc etc etc.

:cry:

Guess I will have to watch, wait, and see.
 

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OK - here is an update on my condition. Took my car to AutoZone to have the new battery checked and the alternator checked. Still planning on re-checking the tranny fluid level too but this was an easy place to start.

First the battery. It was very low despite being charged all night. It read "charge and retest". It did fine under load.

Then the alternator. Got in and held 2000 RPMs. I was 100% prepared for it to be bad. Guess what - it tested OK. I don't know how long this thing will last but that was some good news. During the test the tech noticed as the revs fell to idle the voltage dropped too. He then suspected the battery was bad. We grabbed a new one and then retested and sure enough the voltage remained constant and didn't drop off with load. Kept the new battery and drove around. Didn't seem to be any problems with shifting. No mystery lights coming on.

Next day - fire up the car and drive off. It is wet from rain and a LOT warmer then usual but the car behaved 100% better. The car always seems to be perfect in manual shifting mode - it is just when in normal driving mode when I head out in the morning that it seems to loose power upshifting, hunt for the right gear (feels like slipping clutch) and then bangs into gear sending the car forward.

I will keep testing but maybe this was an electrical gremlin. I will still use the Bentley to recheck my fluid level on the rack this weekend as well.
 

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Transmission Malfunction, Failsafe Mode

Thank you SILVERBULLET5, I have a Ford f150 '05, I was driving when I got that Transmission Malfunction, Failsafe Mode message, I started researching when I came across your post and I opened the hood, the battery posts were covered with that white stuff, so I cleaned everything real good, went for a test drive and I didnt get that message anymore, I hope that took care of that problem, and thank you again

:thumbup:
 

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Hello guys, just want to point out that I, too, am having the same problem. I have a '99 540iAT and the reverse gear was a bit iffy. Sometimes it would work when the car is still fairly cold or have not been thoroughly warmed up and when it has the reverse would be sluggish on flat lands. So you're pretty much stuck if you are driving on a decline and needed to reverse. Anyways, in 2004 I was forced to buy a Remanufactured Tranny from the stealer (Peter Pan BMW in San Mateo) and had my shop in Concord install it. In 2007, the "Trans Failsafe Prog" started showing. I ignored it just because I knew that it couldn't be the Tranny as it is fairly new. It would show up rougly about twice a week. When it does, the car would die for a few seconds while it was still in gear. It would happen also when I came to a stop. It would start eventually, my "clock, radio stations, program for the seats" would be resetted. Lately, when the error shows up, the light for the DSC and brake would be lit. I would lose power on my steering wheel such as horn, volume for the radio, and cruise control. My radio would also stop functioning. I would eventually return, sometimes the duration would be 10 min to 30 or sometimes a whole hour. It's very frustrating. I have an OEM battery and it has a green color on the peep hole, so I would assume it is still good. The batt is about 4 years old. I hope this could be some kind of info for anyone who is trying to decipher this very vague and frustrating error.
 

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Trans Failsafe - no steering wheel buttons - intermitt. seat belt warning - trans o.k

...In 2007, the "Trans Failsafe Prog" started showing. I ignored it just because I knew that it couldn't be the Tranny as it is fairly new. It would show up rougly about twice a week. When it does, the car would die for a few seconds while it was still in gear. It would happen also when I came to a stop. It would start eventually, my "clock, radio stations, program for the seats" would be resetted. Lately, when the error shows up, the light for the DSC and brake would be lit. I would lose power on my steering wheel such as horn, volume for the radio, and cruise control. My radio would also stop functioning. I would eventually return, sometimes the duration would be 10 min to 30 or sometimes a whole hour. It's very frustrating. I have an OEM battery and it has a green color on the peep hole, so I would assume it is still good. The batt is about 4 years old. I hope this could be some kind of info for anyone who is trying to decipher this very vague and frustrating error.
I know this is an old thread, and you only have 8 posts.... BUT, sure would like to know what the resolution was...

I'm getting very similar indicators:

- One night took my right front headlight out to take apart and get rid of the moisture inside it.

- Just 10 minutes after putting it in, took it for a ride - and the seat belt warning light would come on and not go out - even with all the seat belts latched... Driver and passenger in the front. Then it went out after a stop. Next morning similar situation, then at lunch, everything o.k. Thinking microswitch in the drivers seat belt.

- Next night - wash car, test seat belt - it is sort of o.k., think there was an intermittent. Then go to move it and wham - "Trans. Failsafe Mode" and the yellow BRAKE light on the dash are on... WTF...

-- Check trans fluid - nice and red, full

-- Clear trans codes by removing the battery ground for a while and turn lights on.

-- Test battery voltage while sitting there - 12.54 V

-- Test battery voltage/alternator after starting - 14 V ish

-- Move car, starts out o.k., then 100 yards away "Trans. Failsafe Mode" and the yellow BRAKE light on the dash are on... WTF..."

-- I drive it down the road - get this - even though it says TF Mode - it is shifting like it normally does - starts in first, etc. I have sport mode, and I can manually shift through all the gears - Trans seems fine...

This morning - here are some further clues - I notice that I have no functions on my steering wheel - No radio control, no cruise, and no horn...

Seat Belt Warning - Now the little red warning does not even come on...

I did test the ground point near the air cleaner as well - Continuity from the connector to battery ground tested fine with a DVM, and to make sure, I went ahead and took the connector off the stud, no corrosion there, brushed it anyway and put it back on. (I did not think this was an issue because all of my gauges work fine.

OBD II Scan tool showed no codes at all...

Is there a major connector somewhere that could be a problem?

My drivers seat has been intermittent in the past, three times - it stopped all functions, and then when I go to check it out - works fine after testing the power to the connector under it, and resetting the connector once, the other two times - it just started working...

Time to check out the schematics at least, but seriously - if anyone has seen something like this, I would appreciate it...

Thanks.
 

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How do you read the transmission error codes? I have the Pieke tool and I was testing my transmission shifts and it went into failsafe but I couldn't get any codes out of the Pieke (just got the "---")
Peake tools dont read EGS codes. I returned mine just for this reason and purchased the Bavarian Technic software / cable solution, it reads all the modules including the trans EGS.
 

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Thanks. I'm probably buying the BMW softare and interface to be able to test/repair all of my BMW's.
The "real" BMW kit is thousands, Bavarian Technic is $287 or $9ish for unlimited VINs, it reads most BMWs from the 80's. Others to consider, Carsoft and Autoingenuity (I think that is the name)... I liked what the BT web site had to say and called them. Happy with the BT thus far.
 

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Just wanted to close the loop - Ignition switch replacement corrected all of the problems above.

I'm picking up a computer with the BMW software - should work o.k. I have an 04 745Li - and there are no manuals for it...
what made u think to replace the ignition switch?
 
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