BimmerFest BMW Forum banner
1 - 8 of 8 Posts

· Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Hey all, first post b/c this is the first major problem I've had with my Z4.

I have a 2007 Z4 E85 3.0i that came with the standard pleather seats, motorized but NOT heated.

Driver's seat was falling apart, so I was going to replace anyway, but I got a pair of heated seats off eBay to add this functionality. I got the control module too, so that I could turn the seats on and off.

Seats came in, installed everything, all connections are good, but the seats don't work. I have power to the seats, because I can move them, but when I try to activate the heat the light blinks green very quickly then goes away, for both seats.

I asked one of my friends who works at a BMW dealership what could be wrong, and he told me the module needed to be programmed, but that he couldn't do it so I had to bring it in. This was the first trip I've had to make to the dealer.

Just got the call that the dealer couldn't figure it out either. They programmed all the modules, but the seats still do not work. Service advisor said "There appears to be some unplugged connections." So I spent $300 for nothing.

Worth noting these seats are from a 2003-2005 pre-facelift Z4, as evidenced by the 2-pin passenger occupancy sensor, but aside from that one plug on the passenger side all other plugs are good. I have an airbag light on b/c of the occupancy sensor, but the delete should be here in a few days.

What am I missing here? Since my car is apparently not pre-wired for a heated seat option (I would have thought it would be), what connections do I need to make?

I am hoping for a savior here, I have scoured the forums and seen a few dead posts about things similar to this. If you have any idea, please please let me know. I have put so much work into restoring this Z and this is a huge roadblock for me.

Much appreciated,
Sleepy
 

· Registered
Joined
·
5 Posts
Discussion Starter · #2 ·
Since I am doing lots of research on my own, I am hoping to turn this into a retrofit guide for those who are in the same boat as I am. I had a long conversation with the former service manager at the dealership (think he's in sales now) and he recommended a few things for me to do:

First, he told me to abandon the project and put aftermarket heater-pads on, and tie in a switch, call it a day. NEVER.

He then told me he also believes my car is pre-wired to support factory seats. So, unlike many other retrofit guides, I shouldn't have to add any lines to the JBE or VO or whatever. This is because I already had power seats, just not heated seats. If your ride has manual seats, I've read enough forums to know that you will need to handwire seats. this diagram may be useful to you, makes no sense to me:
source page: Heated seats retrofit (now complete) - babybmw.net



Second, he told me to look into coding the VO myself. I am very new to this side of BMW maintenance, so if you're also new, don't worry. VO is Vehicle Order:
For the uninitiated, this is a string of alpha-numeric codes reflect exactly with which options that car left the factory.
(source: Understanding BMW's ZCS System — Bimmer Coding NA)

Most importantly here, in the VO, is the specific alpha-numeric code for the heated seat option, which is S494, also seen as $494.

I am still trying to find the exact module which this will be under. But I'm getting ahead of myself for the others that may come upon this thread and be as lost as I was before hours of research.

First step is to go to bimmergeeks and get the free software:

I downloaded the "Bimmergeeks Standard Tool," "Base," and "E85" packs.

It's important to follow the installation instructions at this step.

Next, you'll need a way for the laptop to communicate with your car, which will require an OBDII to USB cable. I bought this one:

Once I downloaded and installed the software, I opened NCSDummy to feel out the waters, and here is where I am running into my next problem: I can't find the heated seat module.

There are many online, throughout the forums, listed: CAS, IKHA, etc., of which I have none. BUT,

I think this may be due to a few factors:
For starters, my laptop is not connected to my car. I've only ordered the cable today, and it will take a week or so to arrive. Secondly, the module that I placed into my car added heated-seat controls. So, I am hoping that once I hook my computer up to my car, a module will appear in NCS that allows me to activate the heated seat functions.

This is turning into a much larger project than I thought. Plug and play was the expectation, and now I am planning on coding my car.

Continuing my research, I came upon this article, which makes me think modding the module may be simpler than I thought:


If it is that easy, as typing in $494, and having the software handle the rest, my mea culpa may be on the horizon. I feel like this won't be the case, however.

For those stumbling upon this thread, I will update it once the cable arrives and I am able to begin using NCS with my laptop attached to my car. If anyone with greater knowledge than I sees this, please share your knowledge.

Sleepy


saving my research:
USING NCS TO CHANGE VO.pdf (polish, just keep clicking download; it's another NCS guide)
NCS Dummy - Taking the expert out of NCS Expert (NCS dummy guide)
 

· BeeemerBro
5,4,6 BMW X3 All...196K +
Joined
·
5,586 Posts
Well nice post...
Misery does love company.
I too am in the same boat as you.

But I am working on the e83.

I think I started back in September.
Researched , no simply compared the dash control panels and figured it's too much of a headache.
Later after reading more threads and finding several e83s at the boneyards and then I found a pair of dusty e83 seats but in the best condition for the age....the project is on again fiercely.
I've got to get ready for work...but I've found several post that are very encouraging. There's so much more to say on the subject...but it's doable and i think it's easier then we know.
Yours buttons blink!
Iam starting new
Finally, I'm at the point of simply going to the boneyard and removing the wires and transplanting them into my car.
Later here I'll post some of the posts that reignited my efforts.
Here's a main one, enjoy...




Start at 20:50 and enjoy more insight on retro fitting seats power...


Sent from my REVVL V+ 5G using Tapatalk
 

· Registered
Joined
·
5 Posts
Discussion Starter · #4 ·
Here's a complete document list on how to retrofit the heated seats. Problem is, my car was not pre-wired for the heated seats. Here's a complete update:

After everything above, I had the car programmed by a wonderful dude out of Boston, and still the seats didn't work. That's when we realized the car did not have the wiring installed. The wiring harness doesn't have a part number, which will make this search extremely difficult. But that's all I have now after months of research.

:)
 

Attachments

· Registered
Joined
·
1,349 Posts
....So, unlike many other retrofit guides, I shouldn't have to add any lines to the JBE or VO or whatever......
Sorry to disappoint, and as you have almost certainly found out, you need to install all wires and ECU that support the whole heated seat ciruit, which includes replacing the JBE.

BMW DOES custom make wiring harnesses and ECU's specific to the features purchased from the factory. They do not sell all variations of parts over-the-counter, but only choose the least number of part numbers that can support all vehicle order types to minimize their supply chain burden, but ECU's such as the factory installed JBE's have "do-not-populate" sections on their PCB's, so just installing wiring will not equate to success.

In the case of the Z4, if you look up JBE on RealOEM, you'll need the JBE part number that states "heated-seat = YES", which can be sourced "new" from BMW, or "used" from eBay.

Then ensure you've installed all the wires from the factory stated fuse(s) to the seat - ALL wires per TIS. You will not be able to buy a "retrofit" harness from BMW, unless you buy the whole cabin harness (impratical), so you can opt to run your own wires, or get a used harness of eBay.

Good Luck.
 

· Registered
Joined
·
5 Posts
Discussion Starter · #6 ·
Sorry to disappoint, and as you have almost certainly found out, you need to install all wires and ECU that support the whole heated seat ciruit, which includes replacing the JBE.

BMW DOES custom make wiring harnesses and ECU's specific to the features purchased from the factory. They do not sell all variations of parts over-the-counter, but only choose the least number of part numbers that can support all vehicle order types to minimize their supply chain burden, but ECU's such as the factory installed JBE's have "do-not-populate" sections on their PCB's, so just installing wiring will not equate to success.

In the case of the Z4, if you look up JBE on RealOEM, you'll need the JBE part number that states "heated-seat = YES", which can be sourced "new" from BMW, or "used" from eBay.

Then ensure you've installed all the wires from the factory stated fuse(s) to the seat - ALL wires per TIS. You will not be able to buy a "retrofit" harness from BMW, unless you buy the whole cabin harness (impratical), so you can opt to run your own wires, or get a used harness of eBay.

Good Luck.

Replacing the JBE is a must even though I’ve programmed the computer to allow for heated seat functions, or am I misunderstanding a step here?
 

· Registered
Joined
·
1,349 Posts
What's the part number on your JBE? I'll look it up...if it supports heated seats from the factory, then no replacement is required....but if it does not support heated seats from the factory, you'll need to get a JBE that supports heated seats....

But's let's check the P/N first.
 
1 - 8 of 8 Posts
Top