Hitch installs ALWAYS upgrade software?

[Sterling's X]

Hello Everyone,

I have a quick question. I am having a hitch installed on my E70 next Wednesday (on my Birthday no less). I have Nav with Premium sound, but do NOT have the backup camera nor do I have the PDC sensors (kind of wish I did though, loved them on my E53).
After my hitch is installed, will I still need the software update anyway? Not sure what else would be affected, so I figured I'd ask before I get knee deep into it.

Thanks in advance!

Sterling #122

[JCL]

I believe the current version of the instructions says to flash the vehicle. If no update is required, fine, but it is the software that knows that. Safe course of action is to plan to update the software.

If you install it yourself without doing the software, worst case is that you will have electrical malfunctions that will be resolved by flashing the vehicle.

[admranger]

Thought that the software flash also tells the traction/stability/etc. control systems that you have something heavy behind you (when you plug into the 7pin connector, that is). Helps when the trailer tries to wag the X5, etc.

[JCL]

Originally Posted by admranger

Thought that the software flash also tells the traction/stability/etc. control systems that you have something heavy behind you (when you plug into the 7pin connector, that is). Helps when the trailer tries to wag the X5, etc.

I think that is an internet rumour. Other BMW models (like the E53, and the current X3) get the trailer stability control, which is programmed in the DSC system and not the lighting module, without any module reflash (this is specifically referenced in the TIS instructions). They are using the same DSC design, but likely have different parameters. Several posters have referred to the risk of it not working without a reflash, but that doesn't seem logical to me, since the only thing the reflash does is tell the vehicle the trailer lighting module is installed. We can determine if that works, and the module is visible to the system, if the PDC goes off automatically.

All that said, in my years of towing the trailer stability control has never intervened on either my E53 or my E83. That includes towing through the Rockies on snow-covered roads. I would expect to see the DSC lights come on when it does, same as when DSC intervenes without a trailer. I am glad I have it there, but it isn't in play in normal driving when towing, IMO.

[ard]

Originally Posted by JCL

I think that is an internet rumour. O.

agree on the stability stuff.

However with the 2011, it sounds like the programming tells the car to send a brake signal to the rear connector. Without that, trailer lights will not work.

A

[JCL]

Not sure what is different on the 2011, but I think that either the vehicle recognizes that you have installed the trailer lighting module or not after installation. If it does, lights and PDC work. If it doesn't, then brake lights and/or PDC defeat would likely not work.

The newest version of the hitch install instructions I used had specific flash instructions, unlike earlier versions of the same publication. In my case, I didn't need to flash the X3 based on those instructions. If the instructions for the E70 say it needs to be flashed, and those instructions are the most recent publication, I think that would be more accurate than all of our guessing.

[Weasel]

The trailer module that ties it all in with the wiring etc. is a programmed and encoded control module... so it does require programming. And on i-level vehicles like the E70 the software will program anything else it sees needs it to get it to the current integration level.