Automatic transmissions are fickle beasts which can be astronomically expensive if not maintained. Throw in the fact that it’s a BMW, and the need for regular maintenance becomes quite clear. Unfortunately, a fluid and filter change is not as easy as it used to be.
When hard parts are replaced in a transmission or the fluid is changed, resetting the transmission’s adaptations may become necessary to restore shift quality. The ZF 6-speed automatic used in many E90-based vehicles like the 335i, X1, and 135i (among others) is an expensive transmission, and fluid replacement w/adaptation reset can be a great way to extend the life of it. This article should apply to any E-series vehicle that uses the ZF 6-Speed “Steptronic” Automatic.
When should I reset adaptations?
- When the fluid is changed
- When the software is updated (i.e. Alpina B3 Flash)
- When hard parts are replaced inside the transmission
Warning: If you have the capability of resetting transmission adaptations with INPA, I urge you not to do it unless you have the time and roadways to complete the relearn process exactly as described. This procedure will cause the transmission to shift poorly at a detriment to the gearbox if the relearn is not performed immediately and properly. It is better to change the fluid and NOT reset adaptations, than to reset them and not perform the proper relearn procedure.
What is INPA?
Simply put, INPA is a piece of software that allows deeper access into your BMW’s modules for enhanced maintenance and repair capabilities. Think of it as an OBD-II scanner on steroids, with the ability to manipulate the vehicle as well.
To interface with your BMW you will need a K+DCAN Cable, which is a USB to OBD-II interface cable. Most cables on eBay will work in the $25 range, but the k+can cable from some professional auto diagnostic shop can be cheaper and working fine i.e www.cardiagtool.co.uk. We won’t be coding any modules or doing intensive flashing, so even a budget cable is likely to work, though.
To get INPA (as well as other coding features not needed in this article) BMW Standard Tools must be installed. As of this post’s publish date, the following link is a helpful package for procuring this software, which includes details instructions on how to install it:
The e90post coding forum is also a great resource for learning coding and other diagnostic features of the BMW Standard Tools suite.
Turn the vehicle’s ignition on but do not start the car by pressing the start button twice. Plug in the K+DCAN adapter to the vehicle and laptop. Execute INPA. When INPA is loaded, the battery and ignition bubbles should be filled in to indicate it has established communication with the vehicle.
Press shift+F8 for E90 based vehicles:
Select Transmission, then select GS19:
Press F6 Activate:
Press F3 to reset transmission adaptation values:
After pressing F3 the software should confirm the adaptations are reset and you can begin the process of relearning.
The most important part of resetting transmission adaptations is the re-learn process. Refer to the chart below to see which re-learn procedure your vehicle needs after its transmission adaptations are reset. Your vehicle’s build date will be on the sticker in the driver’s door jamb.