Strange auto transmission issues....

[richard300]

Hi All 2010 X1 S-drive with 2.0petrol engine.

Ran this car with no issues at all, then had it sat in my garage for a month as i had purchased a new car.
Advertised the car and someone came to test drive her about 10days ago - She drove faultlessly and they decided to buy the car.
A week later (Sunday 10th) they came back to collect the car and within 500meters the car developed a whole heap of transmission related issues.

The only thing that had changed from test drive to purchase - was that i had attached a battery conditioner.

I gave them their money back and limped the car home (it was jerking in and out of gears and then would run ok, then jerk in and out of gears - and when in park the gear selector 'trigger' would click rapidly on and off.

This morning I thought i would have a look at the car and when i started her there were even more issues.... It went something like this:

Car started with a missfire (which soon cleared)
the revs would hunt (dip) as the trigger for the gear selector would again rapidly start clicking. If i sat with my foot on the brake and changed from Park to N or R or D the selector would continue to click - every time it did so the revs would dip and the indicator would flash from D to P (or R to P is i was in reverse).
Then (still whilst in the garage and with the car in park) the car seemed to run fine all of a sudden (no clicking from the selector or revs dipping) but then the Traction control light came on and then the brake warning light came on and then the gearbox issue resumed.

I have basic Carly scanner and i am now displaying the following codes:

003099 - CAN message EGS missing
00A3AA - Error failure transmission data CAN ID 1D2 error

00578E - Transmission fluid deteriorate: This one has been on the car for months and on Sunday when the issues started, was the only code showing.

00D258 - Transmission data not received (received by DSC control unit)
00277D - Misfiring (cylinder 2) - which cleared.

Anyone had a similar series of events?

[plastoid]

I would start with checking the battery first. The electronics are quite sensitive when they don't receive the right voltage. That said, if the battery is in bad condition, even if it's been trickle charged, it won't do its job properly.

[richard300]

Thanks Plastoid.

To be honest, i attached the battery conditioner because i felt that the car seemed to start just a tiny bit lazily when they came to view the car - Not much and maybe not even at all (and it was just my imagination).
But i had the conditioner in the garage so decided to hook it up anyway.

But my Carly scanner shows the battery as charging at 15.48 volts when running.

I am convinced everything is related to something electrical though, as opposed to mechanical.

[wheela]

I don't have any explanation for your observations, but was going to suggest (as mentioned above) a low battery on these cars seems to frequently be the cause of weird, random, unexplained electronic issues (haven't had to deal with it myself, yet...). How old is your battery? It seems very dubious that this started after connecting the battery tender, that may be clue...

However, I see you mentiond you've had a code for "transmission fluid deteriorate", may I ask if you did anything to try to rectify this during those months? Also, how many miles are on the car? Ever had any transmission service done?

Not too familiar with the workings of the transmission, but I do know that the TCU (transmission control unit) has adaptations, and that it will adapt as components wear over time. Not sure if that code could be related to some adaptation hitting a limit, or warning threshold? I think you're 8AT, right? My 35i has the 6AT, and even though BMW says lifetime fluid, ZF recommends changing the fluid, filter (built into the transmission pan) and mechatronic sleeve every 50,000 - 70,000 miles, or around 7 years I believe. Perhaps if something is going on with your mechatronic sleeve, that could be creating communication problems with your TCU? Just purely guessing.

Like I said, I'm not too familiar with the transmission, but if it was my car, depending on battery age I may start there. If that doesn't fix anything I'd bring it to a bmw shop for evaluation. But I'm also a guy that doesn't do my own maintenance, so it probably depends on your knowledge and comfort level working on it yourself.

[wheela]

Also, i'm not sure what the voltage ranges should be when the car is off, or when running, but I thought alternator voltage was more like 14.4 volts, not sure if 15.4 is too high? These cars have intelligent battery charging though, so not sure what that does to charging voltage. Regardless, to check the battery condition, I believe you'd want to do it with the car off, otherwise you're measuring charging voltage, not battery voltage. Perhaps some other users could chime in with where your battery voltage needs to be? From reading threads, I recall that the threshold for creating electrical issues was a lot closer to 12 volts than I thought it would be (doesn't have to drop much).

Also, what kind of battery tender did you use? If you have an AGM battery, you're supposed to use a special kind of battery tender that is compatible with that battery type.

Community - please correct me if i've butchered any of these details too badly, haha!

[richard300]

Hi all and thank you for your replies....

To answer some of the questions: The car is running the N46 2.0i with the ZF 6HP gearbox. She has covered 83.000miles (134.000km) and whilst there are a lot of service stamps in the book, there are hardly any invoices - so I cant actually confirm if the gearbox fluids and filter have been changed. The battery is a genuine BMW battery but again i don't know how old it is.

So far i have attempted a gearbox reset by holding the pedal down for 30seconds whilst having the ignition accessory 2 position - Nothing changed. I have disconnected the battery for 12 hours and worked my way through the fuses that relate to the issues.

Someone mentioned to me that the initial misfire (that clears) could be the source of all the other issues ??? As opposed to a symptom of the other issues ??

This weekend I will put the car on axle stands and check the gearbox fluid level - If its low i will top up and see if that improves things and i might swap the coils around and see if the misfire changes from cylinder 2 to a new cylinder - And if so i will purchase a new coil pack and see if that helps.

After that i will resort to finding a BMW specialist (easier said than done where i live)

[plastoid]

The reason why I suggested to check the battery first was because I had the experience first hand. It happened when I just purchased my car pre-owned, the dealership told me the car battery is showing signs of age. Meaning that it will start just fine, but it sounded like the crank was a tad too long.

About a month past, I had an issue with engine knocking, so I took it back to the dealership. They scanned the ignition timing and found no problem, and yet the engine still has the knocking issue. Their final solution was to change all the coils (even though scans told them they were running fine). But still they could not assure anything, because the record on their system showed that the coils were recently changed. So I told them to just replace the battery first and see what happens. And yep, the problem's gone.

I also second what wheela said, 134,000km is way overdue for a trans fluid change.

Good luck bro, and keep us posted of any updates.

Oh and also, My X1 is also N46 with ZF 6speed. Most people in this forum are from the states and they have different specs from ours, so I'm kinda happy to bump into someone that has the same car hahaha.

[Gamb1t]

Originally Posted by richard300

The car is running the N46 2.0i with the ZF 6HP gearbox

Huh.... learned something new. I'm beginning to think the ZF 8hp45 is only available with the x28i n20 and the rest gets the older 6hp.
Does the car exhibit herky-jerkiness under manual-mode?

Anyhoo.... I second the suggestion about addressing the battery. Can you pop in a brand new AGM? You would need to have it registered with the ECU.

2ndly, you might want to check the associated fuses. Maybe you have some fuses unseated or corroded.

I also second what wheela said, 134,000km is way overdue for a trans fluid change.

While it's high, there are many cars with far higher mileage running original tranny oil. In fact there are suggestions to leave the tranny oil alone if it has accumulate very high mileage.

[cwickberg]

How did you hook up your battery conditioner? The battery system on BMWs is very complex with lots of sensors and electronics... have you checked voltage, continuity etc back under the rear floor where battery is located?

I had to download bimmerlink app to register the battery when I replaced it last year. Perhaps look into the app to check?

[0w40X1]

AGM batteries on these cars shouldn't see more than 14.7 volts, so something is up with your battery or charging system.

I think AGM's should only be charged not conditioned since the conditioning is designed to stir the free acid which AGM's don't have.

I've seen so many low batteries on these forums be cause of trouble.

[mechatony11]

I apologize for reviving this old thread. I had a similar issue with my car, and it turned out to be a defective mechatronic unit that causes the vehicle to no longer change gears and throw warning messages on dashboard. I did a lot of search on this issue and came on in depth article which may be worth reading, search for " BMW Transmission Problem Explained on YOUCANIC" and you will see an article that goes over common causes and possible fixes
you can read about it yourself. I hope this information can assist someone else with a similar issue.

[RandyM4A1]

Originally Posted by mechatony11

I apologize for reviving this old thread. I had a similar issue with my car, and it turned out to be a defective mechatronic unit that causes the vehicle to no longer change gears and throw warning messages on dashboard. I did a lot of search on this issue and came on in depth article which may be worth reading, search for " BMW Transmission Problem Explained on YOUCANIC" and you will see an article that goes over common causes and possible fixes
you can read about it yourself. I hope this information can assist someone else with a similar issue.

We called it a Valve Body, this happens if you don't change your Transmission fluid at 60k miles (80k KM), there little balls gets stuck from the old fluid dirt buildup in the valve body unit, the shifting solenoid sometimes fails.

What happens when a shift solenoid fails?
a problem with one or more of the solenoids can cause a lack of pressure, resulting in hard, soft or delayed shifts. a failed shift solenoid can also cause transmission slippage, where your engine revs faster but the car stays at the same speed.
Changed and refill only ! do not flush.