If I disconnect the ground battery cable during the install of my PIAA driving lights, what all will I lose or need to have reprogrammed on my 2006 MCS?

 

I disconnected the negative terminal on my '06 MCS cabrio when I put in my Hella lights (you MUST tdo this to assure that you don't fry anything while wiring), and all I needed to reprogram afterwards was the clock. Everythign else on the on-board computer came right back up and everything on the car worked the same as the day I took delivery. I don't know if any custom computer settings (the programmable settings for the auto-locking doors, the low gas ping tone, etc.) are reset when that happens though - I'd call the dealer and ask what happens if the battery is disconnected if yopu're worried - but I'd think that they would NOT, otherwise, if you ever blew the main fuse, for example, then your computer would reset... that would be bad.

 

I believe the only thing that you may lose would be the radio presets. I've had mine disconnected & that was the case for me. Remember you can't open the boot once you've disconnected the battery, only with the release under the rear seat.

Edit...Yep the clock will stop & need a reset.

 

you'll also loose the ECU's adaptive memory and the computer readouts.

honestly, i didn't unplug my battery when i did my PIAA install...
im still here. lol

 

Debateable myth.

Plan on loosing Radio Stations, Clock, one mile off the odometer and thats about it.

 

Just make sure to unlock the boot before disconnecting if you are concerned.

 

that's even more debatable. my radio station did not loose memory
and the odo did not change at all. this is when i actually did the unplug
for more than 10min. computer memory and clock was lost for sure.
and by the way the car ran, i am quite positive the ECU lost the
adaptive settings memory. you won't loose SES light nor EML from
the unplug.

 

Until the last time I did it I'd lose all or most radio stations, last time I lost none. I used to think I lost the adaptive memory, but after having the DME repprogrammed I felt the adaptive porttion dramatically change immedately then all was close to normal after about 500 miles and 2 traffic jams.

Anyway to answer the OP Question no need to reprogram ECU and if you lose the adaptive settings that can only be a good thing as the computer will adjust to the most recent settings.