E90Post
 


Studio RSR
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > DIY Guides > E91 Memory Seat Retrofit



Reply
 
Thread Tools Search this Thread
      07-28-2020, 11:53 AM   #1
swiftryanswift
Registered
swiftryanswift's Avatar
2
Rep
3
Posts

Drives: E91 320d SE
Join Date: Jul 2020
Location: Cheshire

iTrader: (0)

E91 Memory Seat Retrofit

Firstly, my apologies, this has been discussed a lot over the last 10 years and i've done a lot of research, however people haven't shared their trade secrets. Not all of them at least.

I have an 2010 E91 SE, which has heated seats but no IDrive, I've bought some M sport, heated, leather, electric, memory seats. I want to retrofit them which I understand is possible, but i need a little help. They are from a Pre-LCI car so i need to swap over the airbag headrests.

Starting with my drivers seat, the wiring pins i have available are 1,5,8 & 9. The new seat has K Can, so has 2,3,4,7,8 & 13.

My plan so far is to
- merge pins 8 & 13 on the donor seat and connect to pin 8 of the existing harness. This gives me a ground.
- Connect pin 7 on the donor seat to pin 9 on the existing harness. This should give me bolster power.

It's just what i do with the remaining wires that i get stuck with.
What do i need to do, in order to wire in the rest?
I've attached a wiring diagram to show what is left.
I'm based in Cheshire if anyone wants to come and help? However i would appreciate any advice.

The wires on my harness are 1 PWM Heat & 5 Ignition Plus Heat.
On the seat i have 2 & 3 for the K CAN and 4 for Seat Heat Module.

I could live without memory seats if that simplifies things? But need the seat heating functionality.

Thanks
Attached Images
 
Appreciate 0
      07-30-2020, 10:57 AM   #2
swiftryanswift
Registered
swiftryanswift's Avatar
2
Rep
3
Posts

Drives: E91 320d SE
Join Date: Jul 2020
Location: Cheshire

iTrader: (0)

So further research has given me a strategy to try, but would 100% appreciate input from others

To keep my car connector the same, the work will be done to the donor seat harness
- Join Pins 7 & 4 together (Keep Pin 4 connector)
- Move Pin 4 to Pin 9 location (currently empty)
- Join Pin 13 to Pin 8 (Joint ground wire)
- Connect Pins 2 & 3 into a new Wire Terminal Connector
- Join new connector pins 2 & 3 to nearest K CAN H & L
- Fit the seat.

This will make pins 1 and 5 on the cars existing connector redundant, but as the K Can should be passing the signal for the heat seating that should be okay? Fingers crossed.
Appreciate 0
      06-18-2021, 10:15 AM   #3
Red Racer
New Member
Red Racer's Avatar
2
Rep
9
Posts

Drives: 2015 F10 M5, 1991 E31 V12 6sp
Join Date: Jun 2021
Location: Thousand Oaks, Ca

iTrader: (0)

https://www.e90post.com/forums/showt...+seat+retrofit

I used this thread in the forum to help me... good stuff...
Appreciate 0
      12-05-2021, 09:13 PM   #4
Red Racer
New Member
Red Racer's Avatar
2
Rep
9
Posts

Drives: 2015 F10 M5, 1991 E31 V12 6sp
Join Date: Jun 2021
Location: Thousand Oaks, Ca

iTrader: (0)

Update...

The LED module I originally used started to give me issues. So, I went back and re-worked the solution. I started with a timed relay module...

https://www.amazon.com/dp/B07T3KCQZB...roduct_details

This allowed me to program the relay to turn on for 3 sec and turn off for 3 sec. I found that at 5 sec, then 4 sec intervals didn't re-activate the seat module. 3 sec seems to work continuously. It also gave me a higher amp rating which is where LED relay was failing.

Keep in mind this relay module is for 12v options and the seat only likes 5v. So, after the relay, I reduced the voltage to 5v by using a common Buck regulator set for 12v to 5v. There are many options out there... This is the one I picked.

https://www.amazon.com/DROK-Electric...758521&sr=8-17

Now the seat works continuously without any issues. Hope this helps.
Appreciate 1
Reply

Bookmarks

Tags
diy, e91, memory seats, retrofit, seat

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 03:01 PM.




e90post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST