My BMW E90 seat install (3 Viewers)

[zipper]

Ok, this is what we have for E90 manual seats with heat.

I'm assuming 8 and 9 are power, 1 is the signal from the hvac module or whatever in the dash that the e90 switch ribbon cable connects to, and 5 is some sort of unloader signal for ignition startup.

The arrows are the pins that exist, and "P" are passenger seat only. This connector goes to a module under the seat. Different modules exist and this is a "heat" module. This module feeds the backrest and seat heating elements. The backrest has 2 wires, and the seat has 3.

Does the module switch them on at 3 various levels for 3 levels of heat and they are constant? If they are drawing 60 to 120 watts that very may well be the case. If they draw more, the module may be controlling the necessary cycling.

An owners manual may shed some light on the subject if it suggests there is a heat sequence for modes 1, 2 and 3 and not merely heat intensity levels.

Also the BMW OEM retrofit kits are all fused at 30a, so its best to design any wiring to match it current protection.

That all having been said, I think the reality is, I will need to bypass the module and use my own 3 position switch and see if it works. If its too hot I'll know I need to design in some pulse method.

 

[86aggie]

Did you ever figure out the heating control on these seats? On my driver seat, I have 2,3,4, 7, 8, and 13. On the Passenger seat, I have 1 and 4-13.

 

[ArthurFJ]

Did you ever figure out the heating control on these seats? On my driver seat, I have 2,3,4, 7, 8, and 13. On the Passenger seat, I have 1 and 4-13.

Finally someone who has the same setup as me! Did you ever figure out the heating?

I've got continuous use of lumbar, but my adjustments fails after 5 seconds (I know this is normal). I've ordered a 12-5V adaptor so I can give CAN H 5V constantly. Is this what you did with yours?

Do you have another 2 pin plug separate from all this that says, "adaptor CAK PL2" on it?

 

[86aggie]

No, I just ran power to each seat, with a in-line switch for the driver seat, to reset the ‘clock’. Separate power for heating via a bmw seat heater switch. Standby and I’ll post a link to a site that can give you your exact pin out with plug pictures. It will be tonight.

 

[Richfj60]

Looks like mire wiring has been pulled out of the fancy yellow connector. But the pin diagram should help. Unfortunately, not seeing wires for the heat elements (as I suspected, but was hoping...)

 

[86aggie]

Forgot I could see this on my phone. Here’s the link: BMW E90 335i Sedan

That’s what my seats came out of. You can find any bmw seats on the home page.

 

[ArthurFJ]

Hey @86aggie thanks for the link. That definitely helped me identify the connectors and whatnot under the seat. I'm still confused though. What exactly did you connect to your seat heater switch too? Everything I see on there looks like the heat is controlled by CanH and CanL

 

[86aggie]

I don't have the papers in front of me, however, I ran the power wire from the switches( I used a couple of BMW rheostat switches that fit in the coin holder slots in the console) to the power wires of the seat heaters - one for seat, one for back. I ran a ground to one of the seat bracket bolts. I looked a little into the CanBus, and chose not to open that can of worms. There are some solutions out there, but the only benefit I saw was bragging rights that I had done it.

 

[ArthurFJ]

Ok so you ran power directly to the wires coming out of the control unit? Essentially bypassing the "Driver's Seat Module" (A187)? And you just used a simple potentiometer (rheostat switch) to control the voltage going to the heating pads?

I think the two boxes for the seat heating are the brown and black plugs (part X732 and X733)

Thanks again! I really appreciate your help

 

[86aggie]

I'm sorry, I don't have the papers with me, I am out of town. I bypassed the modules - different from driver to passenger side. Correct on the switch type. I think the BMW OEM switching separated the seat from the back, and that did not matter to me, so I am sending the same voltage to both with my set up. Those numbers sound familiar for the plugs.

 

[ArthurFJ]

Ok that's awesome! Thanks again

 

[dcfATL]

Hi
I am on my 2nd drivers seat and the motor is only working intermittently (lumbar works all the time) - passenger seats is perfect
2 reds twister with +
2 browns twisted with -
works perfectly for a few sec - but -then even when I unplug it, and plug it back in -- is doesn't usually work
tomorrow I have a 12->5v thingy coming and will try and power the k_can_h with it -- but the adapter has a space for a ground in and out -- do I just use the same ground as the 12 v power?
I bought a switch anticipating the time out -- but if plugin and unplugging the power doesn't work , I don't see how the switch would help
thanks you so much in advance

 

[Seth S]

Hi
I am on my 2nd drivers seat and the motor is only working intermittently (lumbar works all the time) - passenger seats is perfect
2 reds twister with +
2 browns twisted with -
works perfectly for a few sec - but -then even when I unplug it, and plug it back in -- is doesn't usually work
tomorrow I have a 12->5v thingy coming and will try and power the k_can_h with it -- but the adapter has a space for a ground in and out -- do I just use the same ground as the 12 v power?
I bought a switch anticipating the time out -- but if plugin and unplugging the power doesn't work , I don't see how the switch would help
thanks you so much in advance

View attachment 2953493

View attachment 2953494

View attachment 2953495

Please tell me the wire nuts are just for testing purposes

 

[dcfATL]

ABSOLUTELY!!! -- I had then all crimped and heat shrinked -- but until I get this solved, need easy on easy off.

UPDATE --> it works with a switch - I can trigger the switch, move the seat and then turn off the switch and it works all the time.

I bought a 12v-5v adapter and hooked it up yesterday and the buttons worked but the movement controls still died after 30 secs of no use

Please see attached - what am I don't wrong here -- it's driving me crazy (not a long trip)

 

[dcfATL]

sorry hit reply to quick and no edits here -- I meant with the adapter, the memory buttons worked --- but movement controls still died

 

[Seth S]

ABSOLUTELY!!! -- I had then all crimped and heat shrinked -- but until I get this solved, need easy on easy off.

UPDATE --> it works with a switch - I can trigger the switch, move the seat and then turn off the switch and it works all the time.

I bought a 12v-5v adapter and hooked it up yesterday and the buttons worked but the movement controls still died after 30 secs of no use

Please see attached - what am I don't wrong here -- it's driving me crazy (not a long trip)

View attachment 2954837

On my Saab 9-5 the seat controls will work for a short time after I shut the car off. It almost sounds like your system is timing off due to thinking the vehicle was shut off.

 

[86aggie]

The auto power off is the OEM setup. Once you supply power, you have a limited window of time to use the adjustment buttons. As long as power remains, the 'shut down' remains. If you have an in line switch or disconnect power, then its a couple of minutes as I recall before you can reapply power and have the buttons function. This does not apply to the seat heater.

Are you saying the 'adapter' allowed the seat to keep the memory settings?

 

[Sumguy]

The auto power off is the OEM setup. Once you supply power, you have a limited window of time to use the adjustment buttons. As long as power remains, the 'shut down' remains. If you have an in line switch or disconnect power, then its a couple of minutes as I recall before you can reapply power and have the buttons function. This does not apply to the seat heater.

Are you saying the 'adapter' allowed the seat to keep the memory settings?

It's 1 minute (I have the same seats in a 4runner). Could never get the drivers seat to work like the passenger seat, even with a dual buck converter feeding just the high CAN, just the low CAN line or both (they take different voltages, think one's 5v and the other is 3v?). Someone else on the 4runner forum said they got it working (except memory) with a 555 timer setup that oscillates the power. The cut and paste from that thread:

I wired the signal out to the orange/green stripe wire. I may have needed to play with the jumper setting to get it to work but it was pretty easy.

Anmbest 5PCS DC5-15V 4.2V V-PP to 11.4V V-PP NE555 Pulse Frequency Duty Cycle Adjustable Generator Module Square Wave Rectangular Wave Signal Generator: Amazon.com: Industrial & Scientific

 

[YooperCruiser]

I've got e90 3 series sport seats in mine, I followed this guide and mine work all the time.

 

[86aggie]

I used newtis.info as well. Great source. Unfortunately, BMW made them shut the site down a few years ago. If you go to that site, there is a link to the BMW owned equivalent, behind a paywall. While someone could get a pretty good start from the pages I have, or others may have as well, as I understand, BMW is known for making changes on the fly, repeatedly thru the model year. Look at the realoem page referenced in the video and you will see production dates by months within the same model year...