xHP Transmission Tuner is AMAZING

[Our03z4]

This is for my 2008 Z4C 3.0si with the auto box.

Found this on the UK forum about a year ago and decided to give it a try after being so fed up with the nanny trans. So I ordered the Bimmer Geeks DCAN cable along with the USB-C adapter for my phone. This was needed to be able to run the xHP transmission flashtool app since I didn't want the wireless version. Went ahead and got the mapping add-on as well.

Takes about 30mins to do the initial flash but after that each map flash only took about 3. Pretty slick app all in all and very easy to use. The difference was incredible! My wife and did autoX today and it was nice to finally not be over ridden non-stop by the trans since this has "true" manual mode when using the paddle shifters.

Haven't tried stage one but stage 2 was very nice, much smoother in drive now as well. My wife even noted the difference right away. Also the gear you are in always shows in the cluster instead of when you're only in manual mode. Stage 3 makes the shifts much quicker plus the gear holding is great. I won't use stage 3 all the time as the quicker shifts is a little more jarring, I'll stick to 2.

The kit also has diagnostic code reading and something I though was slick was the transmission health checker, actually shows how much clutch life you have left along with shift pressures.

Just thought I'd share my experience in case anyone else gets annoyed with it as I did. Now time for my new exhaust to be put on!

[Nipsey]

How easy did you find the actual software was to use? I purchased the flash for my 2007 coupe last week and am just waiting on the cable to show up. Had to buy an android tablet as well because the software doesn’t play well with apple I guess.

[Our03z4]

Originally Posted by Nipsey

How easy did you find the actual software was to use? I purchased the flash for my 2007 coupe last week and am just waiting on the cable to show up. Had to buy an android tablet as well because the software doesn’t play well with apple I guess.

I'm terrible with electronics but it was a cake walk. They have a tutorial at the beginning of the app, watch that and it explains everything perfectly. I used my Android phone so can't help ya with Apple. Only takes a few steps to flash. I actually was at a family members B-day and I quickly changed to stage 3 for the ride home, that easy and fast.

Let me know how you like it.

[Nipsey]

I will do that , still waiting on the cable. Ordered on the 4th seems like everything is slower these days.

[Our03z4]

Originally Posted by Nipsey

I will do that , still waiting on the cable. Ordered on the 4th seems like everything is slower these days.

Mine only took about a week from Bimmer Geeks. Did you get tracking yet?

[Nipsey]

Yes and to be fair I guess there was an issue with assembly on their end (bimmer geeks) which delayed them shipping it out. But usps seems to want more time to bond with it or something. It has been in state for 2 days and is still not expected to be delivered until Saturday.

[Nipsey]

Tried flashing today. Tool says to turn off ignition while finalizing flash but it just keeps spinning away and doesn’t complete. Any ideas, I am a little afraid to switch ignition back on but I may try

[Nipsey]

Quick update, even with my apparently inadequate charger hooked up. I had low battery voltage. Boosted it and left it connected and all is well.
Only strange thing was that unless it was a part of the stage 3 flash my backup only took 2 or 3 minutes. Not sure how to confirm if it backed up or not. May look into it later. In the mean time stage 3 seems pretty good. Will do the 50 miles and really try it out.

[Our03z4]

Glad you got it figured out! Sorry I wasn't on sooner to help. Sounds like you may want to get a new battery if your voltage was that low. I hadn't driven my car in a while and it was fine with out one. I think the 1st flash does it which is why it takes almost 30mins. After the 1st time it only takes a few to do anything. Stage 3 is pretty nice especially when at the track but I put it back to stage 2. Just remember in stage 3 it has true manual mode, will be a shocker...it was for me at least since I had forgotten and my shift wasn't overrode by the computer as far as too many rpms.

[Nipsey]

Thanks for the response. The voltage was reading 12 exactly but it was obviously not enough as others have pointed out. As far as the battery goes I will definitely check voltage before starting the next few times. It looks like it was replaced at the dealer before I purchased the car. But I have seen a few shiny batteries fail so you never know. On a good note the program walked me through the flash step by step which was great.
I have done more modifications and repairs than I can even recall back in the days of carburetors and points. Had a Triumph Tr6 that my brother and I swapped a Ford 289 into sort of a poor mans Shelby Cobra. Drove that car from Maine to California and back. But computers still scare me.

[pokeybritches]

It depends on what computer you're flashing, but many of the systems go into a failsafe/emergency mode when communication is lost. For example, the fuel pump will go full bore when it loses communication with the engine computer. My Z4M was pulling 53 amps for 45 minutes during an ECU flash. I imagine a TCU flash would be similar in many ways, so a simple reprogramming effort can use more battery power than expected.

The battery is considered fully discharged below 11.9V and can be damaged if voltage drops further. Depending on the type of battery, lead sulfate can crystallize on the plates, reducing the capacity and the ability for the battery to be recharged. So, there is a big difference between 11.6V (<10% charge) and 12.6V (100% charge). Battery failure during a flash can brick the TCU/ECU, so a good charger is critical.

[Nipsey]

I can’t claim to know the details as well as you obviously do Pokey. But I will not be attempting anymore flashes without a suitably strong charger connected.
This was a toe in the water type of project. I plan on doing a supercharger kit later this year. And like I said the mechanical part doesn’t concern me at all but I wanted to try working with a flash program. The xhp walk through claims you can’t “brick” once it is backed up. Right or wrong that gave me a little confidence and I learned my lesson on battery drain for sure. So I guess mission accomplished.