Lost 2nd gear but now all is well?

[dparm]

Unexpectedly, I got the "transmission malfunction" message on the iDrive screen and I couldn't select 2nd gear. As soon as it was safe to do so, I pulled over, turned off the car, and then restarted it. The message was gone and 2nd gear was fine.

I drove around for the rest of the day (100 or so miles) and the warning never came back nor did 2nd gear feel any different in manual or automatic modes.

Is this something that can be safely ignored, or will something like BMWhat reveal what the issue was? I'd rather not take it to the dealer immediately if I don't have to ($100 deductible), especially since the problem was transient. Interestingly enough, it was just at the dealer last week for the "vehicle check".

[m3ray]

DCT I presume?

[dparm]

Originally Posted by m3ray

DCT I presume?

Yes.

Based on what Benvo has said in other threads, these types of random errors are typically harmless and may not even store a fault code. He went on to say that unless it's easily reproducible, they can probably just be ignored. Nature of the M-DCT beast, I guess.

[Leonardo629]

Dan,

I lost all odd number gears once stuck in a taffic jam on the freeway, got home, restart the car and DCT was able to return to normal.

Never encounter the error again.

[dparm]

Thanks, Leonardo. For now I'll just keep an eye on it. Just a fluke, i think.

[dparm]

This came back today, but turning off the car and turning it on again cleared it. Shrug.

[Harpua]

Originally Posted by dparm

This came back today, but turning off the car and turning it on again cleared it. Shrug.

From what I can gather from reviewing the info on this forum, it must be the rod bearings.

[BPMSport]

If it said transmission malfunction, there should definitely be a corresponding fault code stored. DCT does have its quirks, but now that it's happened twice I would rule this out.

[m3ray]

Originally Posted by Harpua

From what I can gather from reviewing the info on this forum, it must be the rod bearings

lol

[dparm]

Originally Posted by Mike Benvo

If it said transmission malfunction, there should definitely be a corresponding fault code stored. DCT does have its quirks, but now that it's happened twice I would rule this out.

Mike, is that something that can be checked with a basic Bluetooth/wifi (and the BMWhat app) reader, or is it going to be buried in the innards of the TCM?

Car has a BMW EVP warranty, so I'd have a $100 deductible. I would just feel stupid if they don't find anything or say "oh we cleared it, it's no big deal."

[BPMSport]

Originally Posted by dparm

Mike, is that something that can be checked with a basic Bluetooth/wifi (and the BMWhat app) reader, or is it going to be buried in the innards of the TCM?

Car has a BMW EVP warranty, so I'd have a $100 deductible. I would just feel stupid if they don't find anything or say "oh we cleared it, it's no big deal."

As long as it reads from the GS40 (DCT/DKG) controller, then it should show up. We can also check remotely if necessary. I agree that throwing $100 and time away with no repair is not advantageous. Given that, you might want to see if the problem persists before taking it in.

[dparm]

Originally Posted by Mike Benvo

As long as it reads from the GS40 (DCT/DKG) controller, then it should show up. We can also check remotely if necessary. I agree that throwing $100 and time away with no repair is not advantageous. Given that, you might want to see if the problem persists before taking it in.

I talked to the developer for BMWhat and he said that it does, so I'll be taking that route for the time being. Thanks for the assist, Mike!

[dparm]

Originally Posted by Mike Benvo

As long as it reads from the GS40 (DCT/DKG) controller, then it should show up. We can also check remotely if necessary. I agree that throwing $100 and time away with no repair is not advantageous. Given that, you might want to see if the problem persists before taking it in.

Finally got the Wi-Fi dongle and used the free app. I see these codes:

3. Transmission Control:
<--------------------------->
Transmission / Getriebe GS 19:
- Fault: sorry, unknown DTC fault
- Code: BMW 5A45
- Fault: sorry, unknown DTC fault
- Code: BMW 5A43
- Fault: sorry, unknown DTC fault
- Code: BMW 5A44
- Fault: sorry, unknown DTC fault
- Code: BMW 5A41


Not sure what the 5A43 and 5A45 are, but I did find two BMW diagnostic docs for the others posted right here on M3post earlier this year:


5A41 = P17BE = "DKG Pressure Sensor, Clutch 1: Total Failure"
The doc says this will indeed put it in limp-home mode and locks out gears 1/3/5/7. That doesn't jive with no second gear that I experienced.

5A44 = P17A1 = "DKG Clutch 1: Incorrect Pressure"
Same as above...this only seems to correspond to the odd-numbered gears.



Is it safe to clear these codes and see if they return? There were some other random codes in other modules but they could be very old and no longer a problem. The paid version of the app says: "With the app’s full version you can inspect each fault in detail, clear faults selectively, and generate the fault report yourself."

The only others that stood out (and could be related), were:

Dynamische Stabilitaets Kontrolle / DSC:
- Fault: Gear data error PT-CAN / CAN CAN BUS open F / CAN message LWS / CAN error message
- Code: BMW D357

Instrument cluster / Kombiinstrument:
- Fault: CAN signal fault transmission / CAN ID failure
- Code: BMW A3AA

- Fault: CAN signal fault DSC
- Code: BMW A3B9

- Fault: sorry, unknown DTC fault
- Code: BMW A562

[PorkchopExpress]

If you tell the BMW tech the codes you threw, they can tell you if you should bring it in and spend the $100. It might be something as ridiculous as a faulty sensor causing a bunch of unrelated faults.

Or better yet, call a trusted indi shop ask them what they think.

[dparm]

Originally Posted by PorkchopExpress

If you tell the BMW tech the codes you threw, they can tell you if you should bring it in and spend the $100. It might be something as ridiculous as a faulty sensor causing a bunch of unrelated faults.

Or better yet, call a trusted indi shop ask them what they think.

The car was in for the CBS "vehicle check" after the first time this happened, which would include checking for codes, as I understand it. They didn't make any mention of these faults to me.

[BPMSport]

5A41:
Fault text DKG: Pressure sensor, clutch 1: total failure
Fault description Clutch 1 Pressure Sensor Plausibility due to Sensor Drift

5A43:
Fault text DKG: Pressure sensor, clutch 2: total failure
Fault description Clutch 2 Pressure Sensor Plausibility due to Sensor Drift

5A44:
Fault text DKG: Clutch 1: incorrect pressure
Fault description Clutch 1 Hydraulic Circuit Pressure Too Low

5A45:
Fault text DKG: Clutch 2: incorrect pressure
Fault description Clutch 2 Hydraulic Circuit Pressure Too Low

Does not look good... Something is definitely wrong..

1st step: -> Read out raw data [clutch 1 pressure sensor, clutch 2 pressure sensor]
Tolerance range: 0.2 bar < pressure < 1.8 bar

1st step: Case 1: Pressure in one of the / both clutches
outside tolerance range 2nd step: Defective pressure
sensor(s)
=> Replace E-module

1st step: Case 2: Pressure in both clutches within tolerance
range 2nd step: => Continue with fault analysis

2nd step: Read out fault category
Precondition: Both transmission units in neutral, engine running
2nd step: Fault category 0, 2 (undefined, offset error):
=> Apply pressure to both clutches
Test routine 'Test_Offset_K1-2_02 '

2nd step: Case 1: Pressure difference </= 0.5 bar 3rd step:
=> Delete diagnostic fault code

2nd step: Case 2: Pressure difference > 0.5 bar 3rd step:
Pressure sensor offset too high
=> Replace E-module
2nd Fault category 4, 8 (short circuit or open wire):

Fault status
2nd step: Case 1: Persistent error 3rd step: Defective
pressure sensor(s)
=> Replace E-module

2nd step: Case 2: Sporadic error 3rd step: => Delete
diagnostic fault code

Good luck and keep us updated. Make sure the transmission has the proper amount of fluid as I've seen the units leak before causing failed clutches and low hydraulic pressure. It's strange to see these faults on both clutches.

[dparm]

Just had this return -- car decided it didn't want to give me second gear and showed the yellow cog on the iDrive screen.

I think it's related to MDM, as I could *sort of* make it come back by switching to MDM but not if DSC was fully engaged/fully disengaged.

Any ideas on what else to check here or simple diagnostics before going into the dealer? It's going to be a hassle if I take it to the dealer since it is happening so rarely. Carly (formerly BMWhat) can read the transmission computer, as I had previously stated. Maybe I'll just fork over the $50 for the app and look at those codes.


(BTW, the car is stock, running 240E + US DCT software as flashed by the dealer)

[henz321]

hey guys, i am having this similar issue on my bmw 335i e92 DCT 2009. I am from Sydney Australia. (hopefully it's ok for me to post in this thread even though i don't have an M3)

I took it to BMW to get a diagnostic done for which i paid around $160. They gave me a one page fault summary which says "possible cause(s) of fault: System leak or hydraulic pump defective. DKG Clutch Pressure fault". It also showed this diagram "schematic structure with sensors", not sure what it meant and if this is just a diagram or was it actually my tests result, i couldn't tell.

Since i am out of warranty, they gave me an option of buying a new transmission for around $20k AUD to which i said no thanks.

My symptoms are similar, every few weeks i would get a Transmission fault error come up on my dash and the gears would not go up and it would only go down in odd numbers. I would then have to slow it down until it is safe to stop then turn off and on the car and the error would go away and my car would drive again normally. This issue occurs very randomly.

I might have to take it around to different gearbox workshops to get some more quotes since i can't afford to buy a whole new transmission from BMW and the car is worth around $35k these days.

i was planning to just wait around since the DCT is quite new for the 2009 model of my car to see if anyone else experiences these issues and what they did to resolve it without warranty.

[dparm]

Henz,

Since mine is so hard to reproduce and I am under warranty, I've largely ignored it.

Have you checked the fluid level or inspected for leaks? Those should be fairly easy.

Originally Posted by henz321

hey guys, i am having this similar issue on my bmw 335i e92 DCT 2009. I am from Sydney Australia. (hopefully it's ok for me to post in this thread even though i don't have an M3)

I took it to BMW to get a diagnostic done for which i paid around $160. They gave me a one page fault summary which says "possible cause(s) of fault: System leak or hydraulic pump defective. DKG Clutch Pressure fault". It also showed this diagram "schematic structure with sensors", not sure what it meant and if this is just a diagram or was it actually my tests result, i couldn't tell.

Since i am out of warranty, they gave me an option of buying a new transmission for around $20k AUD to which i said no thanks.

My symptoms are similar, every few weeks i would get a Transmission fault error come up on my dash and the gears would not go up and it would only go down in odd numbers. I would then have to slow it down until it is safe to stop then turn off and on the car and the error would go away and my car would drive again normally. This issue occurs very randomly.

I might have to take it around to different gearbox workshops to get some more quotes since i can't afford to buy a whole new transmission from BMW and the car is worth around $35k these days.

i was planning to just wait around since the DCT is quite new for the 2009 model of my car to see if anyone else experiences these issues and what they did to resolve it without warranty.

[Pro-AM3]

If you guys keep getting the faults, chances are some teeth sheered off..

http://www.n54tech.com/forums/showpo...6&postcount=94

[F1HHR]

Hi guys,

iv been getting the same errors on my car too:
5a43 pressure sensor clutch 2 total failure
5a44 clutch 1 incorrect pressure
5a5b control valve PV7 valve jammed
5a45 clutch 2 incorrect pressure

apart from that shes fine lol

i just want to know, is there a chance it could be the actual gearbox which is faulty/ or is it the clutch? has anyone managed to fix this?

i thank you all for any possible input. stay safe

[JDM_CL9]

Any chance your transmission is leaking fluid? The sensor will read low pressure etc. if you're running low.