[jp77]

I've checked the forums to the best of my ability, and haven't found anyone with the exact combination of malfunctions. I'll apologize in advance if this has been previously covered, as this is my first-ever post to any forum.

I purchased my 2008 335i sedan about one month ago, and it's had these warnings on the dash since I've owned it:

- Active Steering Malfunction
- DSC Malfunction
- "BRAKE" in yellow (I assume it's related to the iDrive saying "DBC malfunction)

A friend of mine checked the OBD with his laptop, and it listed the following codes; reading:

006146 - AL: Control unit cannot change to active mode, undervoltage
00614A - AL: Motor position sensor: not initialized

The steering feels heavier than it should. The power steering fluid level is fine, and the battery was checked today (14.3V @ idle). Additionally, I checked the corresponding fuses and they are all fine.

Does anyone here have experience with this same group of codes? Are they all related to a single part in need of replacement/cleaning? Any recommendations on my next troubleshooting steps are greatly appreciated.

[lookalikehuuh]

Have you had anyone attempt a recalibration of the active steering?

My buddy's 5 series had somewhat similar issues when his battery died and he had to use a jumper box. We used my Autel MK808BT to go thru the relearn procedure which removed the codes and fixed his heavy steering, until his battery died again and we had to do it again.

Unfortunately your a bit far for me to lend you my Autel but if you can get ISTA or INPA setup on a laptop with an OBDII cable you should be able to do it yourself easily.

Also important to know if they are currently active codes or history codes. I assume the undervoltage would be a history code but if its current you may have an issue with power supply to the actual steering system.

[NGEE]

At least on the E46, the "trifecta" of lights generally means a bad ABS unit. Not sure on the E90.

https://www.e46fanatics.com/threads/...fecta.1220690/

[jp77]

Originally Posted by lookalikehuuh

Have you had anyone attempt a recalibration of the active steering?

My buddy's 5 series had somewhat similar issues when his battery died and he had to use a jumper box. We used my Autel MK808BT to go thru the relearn procedure which removed the codes and fixed his heavy steering, until his battery died again and we had to do it again.

Unfortunately your a bit far for me to lend you my Autel but if you can get ISTA or INPA setup on a laptop with an OBDII cable you should be able to do it yourself easily.

Also important to know if they are currently active codes or history codes. I assume the undervoltage would be a history code but if its current you may have an issue with power supply to the actual steering system.

lookalikehuuh

Thanks for the reply. There was a discomfortingly long list of history codes, but the two codes listed in my post are the only "active" ones.
Regarding the recalibration procedure, I took it for a bumper to bumper inspection at my local BMW mechanic (private, not dealership), and they attempted a recalibration several times to no avail.
When you say "an issue with the power supply", are you referring to the wiring that feeds into the active steering electronics on the steering rack? I figured it couldn't hurt to try to clean the wheel sensor behind the steering wheel, maybe that would have something to do with it... then check the module under the seat for corrosion.

[jp77]

Originally Posted by NGEE

At least on the E46, the "trifecta" of lights generally means a bad ABS unit. Not sure on the E90.

https://www.e46fanatics.com/threads/...fecta.1220690/

NGEE Thanks, I'll definitely look into that as well.

[lookalikehuuh]

Originally Posted by jp77

lookalikehuuh

Thanks for the reply. There was a discomfortingly long list of history codes, but the two codes listed in my post are the only "active" ones.
Regarding the recalibration procedure, I took it for a bumper to bumper inspection at my local BMW mechanic (private, not dealership), and they attempted a recalibration several times to no avail.
When you say "an issue with the power supply", are you referring to the wiring that feeds into the active steering electronics on the steering rack? I figured it couldn't hurt to try to clean the wheel sensor behind the steering wheel, maybe that would have something to do with it... then check the module under the seat for corrosion.

Ah, this is starting to smell like a potential bad ground or bad connection/blown fuse somewhere since the module is specifically calling out an "undervoltage" condition. I would start by testing voltage at the connectors to ensure there is no issue with power getting to the unit.

Any chance you can give us the list of other codes that were not currently active? Sometimes a non-active code can give us more information on where a potential root cause is coming from, especially electrical related issues.

[jp77]

Today I removed/cleaned with alcohol the steering sensor behind the steering wheel; still no Active Steering..

[jp77]

Originally Posted by lookalikehuuh

Ah, this is starting to smell like a potential bad ground or bad connection/blown fuse somewhere since the module is specifically calling out an "undervoltage" condition. I would start by testing voltage at the connectors to ensure there is no issue with power getting to the unit.

Any chance you can give us the list of other codes that were not currently active? Sometimes a non-active code can give us more information on where a potential root cause is coming from, especially electrical related issues.

@lookalikehuuh

Here is a list of all of the codes, active & inactive:

(When I purchased the car it was misfiring, so that could explain the misfire codes. Since then I've replaced the plugs & coils, so that's no longer an issue)

[lookalikehuuh]

Originally Posted by jp77

@lookalikehuuh

Here is a list of all of the codes, active & inactive:

(When I purchased the car it was misfiring, so that could explain the misfire codes. Since then I've replaced the plugs & coils, so that's no longer an issue)

There are quite a few voltage related issues in your list, have you tried doing a clear of all 14 codes to see if that changes the car's behavior?

I need to go try to find a wiring diagram for your car to see how the active steering system is configured as both of my cars don't have it so I'm not super familiar with it. Can you PM me your VIN so I can look it up?

[F31B48]

Have you checked the alternator voltage under load? eg with lights, heater fan, a/c, heated rear window switched on?
Sometimes alternators can test ok with no load, but when load is applied, the voltage can drop dramatically. Try doing the loaded test.

[ptpending]

active steering is quite rare option and that means that you have special version of the steering rack and additional active steering ecu near FRM and CAS.
So you have to check both these devices connector and state.

[jp77]

Originally Posted by EvaBmw

Have you checked the alternator voltage under load? eg with lights, heater fan, a/c, heated rear window switched on?
Sometimes alternators can test ok with no load, but when load is applied, the voltage can drop dramatically. Try doing the loaded test.

@EvaBmw

You bring up a good point. I'll have to try testing it under load. I've only tested it at idle.

[jp77]

Originally Posted by ptpending

active steering is quite rare option and that means that you have special version of the steering rack and additional active steering ecu near FRM and CAS.
So you have to check both these devices connector and state.

@ptpending that's what I plan on doing soon. Checking both units. I known the FRM is under the passenger seat. Do you know the precise location of the CAS?

[ptpending]

no, FRM is in drivers footwell, on the car sidewall between door and engine compartment

[jp77]

Originally Posted by ptpending

no, FRM is in drivers footwell, on the car sidewall between door and engine compartment

Oh; thanks for the clarification. You saved me from quite a bit of time wasted lol.

[e91Owner]

If this was already mentioned, I missed it. When you disconnect the battery you will get the 00614A fault.

To fix it, you turn the steering wheel all the way to the left stop and that back around to the right stop.

[gbalthrop]

I'm NOT personally familiar with Active Steering. However one of your two fault codes has the following "Definition":
6146 | AL: Control unit cannot change to active mode, undervoltage | afs_70

There are several different "Variants" of AL (Active Steering) Module, so check "Info" for yours to see that it's "afs_70".
If so, check fuse F45 per the attached ISTA ScreenPrint. ALSO check for Voltage at Pin#1 & Ground connection
at Pin#2, at AL Connector X13718, per 2nd & 3rd attachments.

Also, since you have ISTA, select line with "6146 code and click "Calculate Test Plan" button at bottom-right of screen.
You will then get "Directed Troubleshooting" or a "Trail of Breadcrumbs".
George

[jp77]

@gbalthrop Thanks for the reply & helpful chart. I'll see my friend with the cable & laptop soon, so hopefully we'll be able to figure it out.

[jp77]

@gbalthrop I have a voltage meter. When I check the voltage @ pin #1 & ground @ pin #2, should I have the car battery connected? I'm not sure of any other way to do so..

[jp77]

I plugged the laptop into the car again the other day. Basically, there are a lot of communication errors. I'm not even sure why it's saying some of those exist. (The fuel pump communication error, for example) the car runs fine. I assume this whole Active Steering issue can be narrowed down to a wiring issue?

[Hoody007]

Originally Posted by jp77

I plugged the laptop into the car again the other day. Basically, there are a lot of communication errors. I'm not even sure why it's saying some of those exist. (The fuel pump communication error, for example) the car runs fine. I assume this whole Active Steering issue can be narrowed down to a wiring issue?

What cable are you using? I wonder if it’s that simple…
On my E31 I had several issues communicating with modules until I tried a different (more expensive) cable. The newer cars tend to be much more forgiving, but I wonder if that’s somehow the root cause.

[F31B48]

Make sure your latency timer is set to 1 in the com port settings. That's probably why you are getting the communication faults. Windows has a habit of changing the setting after doing an update.