Servotronic on a 335i

[doublespaces]

jbbf looks good... take a look in ncsdummy and check the definition file to see if you have options for servotronics

plug pinout looks right... try to stick the wire into the plug...you will understand...

+/- can be found on one of the pics in the 1st/2nd page... worst case you hook it up wrong and your steering will be heavier

and steering rack clunk.. its pretty loud and you can feel it in the car when it clunks... i hope the electronics fix it but....

EDIT:
On the wds diagram on the first page, pin 5 is the Black/Brown wire and pin 6 is the Black/White wire. Had to figure out what SW/BR and SW/WS meant.

Edit 2: Feeling stupid because this information was quoted in my first post. I think I have information overload

Here is an updated photo:

 

[doublespaces]

I also found this which you may already know but found it interesting nonetheless, it may be possible to code/program out those low assist areas at low RPM by compensating for the weaker PS pump by overdriving this 'characteristic curve'.

The characteristic curve for the speed-dependent activation of the Servotronic valve is stored as codable in a non-volatile memory.

The characteristic curve for the speed-dependent activation of the Servotronic valve is stored as codable in a non-volatile memory.

 

[AzNdevil]

While looking at @doublespaces 's post regarding pin out...I realized an issue on my end.

Since the servotronic motor is controlled by a pwm signal, this means it can go forward AND backwards (left and right respectively). This means I will need to figure out if the wheel is being turned left or right in order to send the proper signals to the motor.

This also suggests the older posts' testing method of using a manual pwm motor controller board doesn't work since it will provide power only one way, the steering will be assisted only to one side but there will be more resistance if its turned the other way.

This might work out to be too much effort afterall so I looked further into @R.G. 's idea of retrofitting the JBBF module.

jbbf 1st revision = jbbf81

jbbf 2nd revision = jbbf70

jbbf 3rd revision = jbbfr3

• pre 07/03 and 07/03 - 07/09 cars are compatible with jbbf81 and jbbfr3. they share the same jbbf zb number
• post 07/09 cars are compatible with jbbf70 and jbbfr3
• even though pre 07/09 and post 07/09 both have jbbfr3, hardware zb numbers are different

red square = no servotronic
green square = servotronic options available

Conclusion
On a 3 series, if you are pre 07/09, fitting a jbbfr3 module might solve the signal issue in theory.
Post 07/09 should already have jbbf70 by default so the signal should be there.

Which brings me to... should I get a jbbfr3 module to experiment with... it's ~110 USD shipped...

 

[doublespaces]

While looking at @doublespaces 's post regarding pin out...I realized an issue on my end.

Since the servotronic motor is controlled by a pwm signal, this means it can go forward AND backwards (left and right respectively). This means I will need to figure out if the wheel is being turned left or right in order to send the proper signals to the motor.

This also suggests the older posts' testing method of using a manual pwm motor controller board doesn't work since it will provide power only one way, the steering will be assisted only to one side but there will be more resistance if its turned the other way.

This might work out to be too much effort afterall so I looked further into @R.G. 's idea of retrofitting the JBBF module.

jbbf 1st revision = jbbf81
View attachment 3372
jbbf 2nd revision = jbbf70
View attachment 3371
jbbf 3rd revision = jbbfr3
View attachment 3373

• pre 07/03 and 07/03 - 07/09 cars are compatible with jbbf81 and jbbfr3. they share the same jbbf zb number
• post 07/09 cars are compatible with jbbf70 and jbbfr3
• even though pre 07/09 and post 07/09 both have jbbfr3, hardware zb numbers are different

View attachment 3370
red square = no servotronic
green square = servotronic options available

Conclusion
On a 3 series, if you are pre 07/09, fitting a jbbfr3 module might solve the signal issue in theory.
Post 07/09 should already have jbbf70 by default so the signal should be there.

Which brings me to... should I get a jbbfr3 module to experiment with... it's ~110 USD shipped...

07/09 as in, September 2007?

And yes, may as well buy one and see what happens.

 

[R.G.]

Azn,

The jbbf is pretty simple to remove / replace if it is similar mounting to mine. Two connectors in the front under kick panel, right under fuse box. I've replaced a fuse box on an e90 and really that wasn't much more work either. There was 2 little SOB screws that were headache but other than that pretty straightforward.

If you do have to replace fuse box (thought you mentioned that), couple of things to keep in mind.
1) Take several photos of existing fuse box lay out prior to pulling fuses.
2) There are TINY X shaped fuses in the fuse box that are easily missed. Make sure you swap those to new box as well.

 

[AzNdevil]

Azn,

The jbbf is pretty simple to remove / replace if it is similar mounting to mine. Two connectors in the front under kick panel, right under fuse box. I've replaced a fuse box on an e90 and really that wasn't much more work either. There was 2 little SOB screws that were headache but other than that pretty straightforward.

If you do have to replace fuse box (thought you mentioned that), couple of things to keep in mind.
1) Take several photos of existing fuse box lay out prior to pulling fuses.
2) There are TINY X shaped fuses in the fuse box that are easily missed. Make sure you swap those to new box as well.

thanks rg... if i get the correct jbbf module i shouldnt need to replace the fusebox...but glovebox needs to come out to get to the two screws you mentioned

also.... its kind of a gamble to buy something and only have a 50/50 chance for it to work

since i am already working on something... i will probably finish it off first if i can unless i run out of skills...or processing power on the arduino

 

[doublespaces]

thanks rg... if i get the correct jbbf module i shouldnt need to replace the fusebox...but glovebox needs to come out to get to the two screws you mentioned

also.... its kind of a gamble to buy something and only have a 50/50 chance for it to work

since i am already working on something... i will probably finish it off first if i can unless i run out of skills...or processing power on the arduino

Any hints on how/where to run the wire from the connector to the valve? Think I'm going to take it on in the next day or so and was hunting for any info

 

[doublespaces]

Well i tried to put the rack in and the steering column is too long... Do i need to buy the m3 version? The stock rack isn't as big.

 

[doublespaces]

Nevermind I got it mounted, but i have no idea if the wheel is going to be straight. I need to install tie rods now.

The m3 rack had an extender piece:

 

[AzNdevil]

Any hints on how/where to run the wire from the connector to the valve? Think I'm going to take it on in the next day or so and was hunting for any info

well.. im rhd so i might not be of much help but if i was to do it on a lhd car, plug it in get the wirr out between.front subframe and.chassis and run it along.the abs/brake pad wire into the engine bay and into the cabin

Nevermind I got it mounted, but i have no idea if the wheel is going to be straight. I need to install tie rods now.

The m3 rack had an extender piece:

View attachment 3453
View attachment 3451 View attachment 3452

ahh the original post asks you to use.your old plate... the m3 one will fit too but its close to impossible to tightened down

and the wheel issue... as long as you are close enough... it can be sorted after an alignment... i still havent got new tires or aligned my car yet...

 

[doublespaces]

well.. im rhd so i might not be of much help but if i was to do it on a lhd car, plug it in get the wirr out between.front subframe and.chassis and run it along.the abs/brake pad wire into the engine bay and into the cabin



ahh the original post asks you to use.your old plate... the m3 one will fit too but its close to impossible to tightened down

and the wheel issue... as long as you are close enough... it can be sorted after an alignment... i still havent got new tires or aligned my car yet...

I think the main thing is having my wheel centered while I'm in the center of the locks. Technically I could be pointed straight with one turn to the right and three turns to the left (or however many there are). I'm going to have to go lock to lock and make sure my wheel is straight when its centered. I'm going to have to take this rack off most likely in order to re-adjust the 'center' so I'll stick it on, didn't even think about that as it was 3AM.

 

[AzNdevil]

I think the main thing is having my wheel centered while I'm in the center of the locks. Technically I could be pointed straight with one turn to the right and three turns to the left (or however many there are). I'm going to have to go lock to lock and make sure my wheel is straight when its centered. I'm going to have to take this rack off most likely in order to re-adjust the 'center' so I'll stick it on, didn't even think about that as it was 3AM.

ouch so you are close to redoing the whole install again....anyways i am still testing my code against the canbus data i have captured

the pwm board arrived so i can test it after i finish the coding side...should be relatively easy to test than the code for analyzing the canbus data

 

[doublespaces]

I wasn't actually turned that way, i was just concerned. But I got it basically as close to center as possible. One and a quarter turns from lock both ways.

 

[AzNdevil]

yea seems about right...you got it! did you put your car back together yet? or is it still in pieces?

quick update from my side

code for extracting the canbus data to control the pwm board is done...

this is tested this by feeding data dumps from my previous drives through another arduino with another canbus module

pwm board works without any load

so... all i need to do is wire this and test it in the car....
if it works i can shrink this by a lot and get rid of the lcd as well

 

[AzNdevil]

ahh forgot to post the important bit i found in the jbbf definitions.... guess what this is?

 

[doublespaces]

ahh forgot to post the important bit i found in the jbbf definitions.... guess what this is?

View attachment 3474

Does this mean you can tune the assist? If so I think I predicted that. Now we can have servotronic tuners @Twisted Tuning

 

[AzNdevil]

no progress update... but i was coding a 09 335 with a n55 + dct and it has a jbbfe2

easiest way to distinguish is....it shows up in ncsexpert as 2jbbf when you choose modules

oh and...i did a u turn at 20-30km/h and traction control triggered... dont know if my tires were really spinning or the car doesnt like the wheel being turned too fast... from what ive heard this happens to subbies as well...

 

[doublespaces]

Interesting.. Is it repeatable?

 

[AzNdevil]

couldnt get a better video...hard to turn the wheel with one hand and hold the phone steadily with the other but.... it works!

 

[doublespaces]

So you are able to control the servo?

I got my car running(kind of) and the steering feels good. It just needs an alignment now. It made a hell of a noise when it was trying to pump through the air pockets, but after driving it a little bit and putting more fluid in, its quiet now.