E90 2008 328xi - trifecta warning lights

[RockOn]

Seems every 6 months, I am starting to have some of the common issue but can’t complain as the the car is at 180,000.

Have the common ABS, Brake and 4x4 lights as of two days ago. Hear a slight clicking at low speeds when road noise isn’t that loud.

Here is what I have researched on the forum and other places but seems to be a slight difference between the model years. And after reading, my contributing factor may be that I have been managing a slow leak in one of the tires hence probably stressing the transfer case some.

Most of the info is on the simple actuator gear replacement (one or both of the plastic gears that interact with the worm gear) for X series.

On the 2008 328xi model, looks as if it’s a slightly difference module and there is a metal gear on the outside of the module.

For this 2008 module, is the plastic gear replacement still applicable but some additional disassembly is required?

I’m pulling it apart this weekend, but would like to have the part available for immediate repair. I have options to get a full used module for $200 but if I can manage the gear repair for this model I will try that.

Thanks in advance.


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[328 Power 04]

I wouldn't start repairs before getting a scan of the codes in DSC/ABS, transmission, transfer case, and engine modules.

You must get the codes. Then post here.

[RockOn]

Yeah I have them:
B0A5 road speed signal
5463 VGT faulty mechanism
54C6 VGT Oil wear
5F3A DSC transfer case Internal

Thanks


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[jclausen]

Check the actuator gear

[RockOn]

Yes based on research on this issue that’s the plan for the weekend. Thx


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[328 Power 04]

Agreed with the above.

The road speed signal error, is that in DSC?
Are all wheel speed sensors reading correctly?

[RockOn]

Road speed signal is CAS module. Sorry I didn’t put that.

I’m using a Foxwell NT510.

Not sure how to check each wheel sensor independently.

I will pull the actuator (test the motor and inspect the worm gear) and post back what I find/see.






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[shadowpuck]

foxwell will definitely read the speed sensors - it'll be under live data - i'd check the ABS/DSC/traction control areas....

[bmwdirtracer]

Yeah, the "faulty mechanism" is likely the actuator. But it's quite possible you need a transfer case. The chain gets grossly slack, on many of these.

I would not bother taking the old actuator off until you have the new gear in hand. Try Odometergears.com

Which module is the "road speed signal" code in? Does the speedometer work?

[RockOn]

Speed sensor is in the CAS module and the speedo works fine.

I did more research and it’s the 08 model that needs often the worm gear replacement - not the plastic gear which is what I know at first. Not sure I want to buy that and then ave it be the whole transfer case.

But agree, could be the transfer case. There was no intermittent build up to the event, it just happened. The car has over 180,000 miles and I’ve owned it since 34,000 so I know I haven’t done anything to the driveline except a front drive shaft.

Thanks


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[RockOn]

So just getting in to this and under the car.

Initial perspective is that I don’t think it’s the actuator. A good amount of trans fluid in the surrounding area to the point of minor drips.

If just a bad actuator thinking this area would still be dry - yes/no?

I know there are some o-rings on the motor. For this model 08 328xi, does the external actuator gear go in to a “wet” area?

If so, maybe bad o rings due to metal from the worm gear, but now I’m hesitant to even try to pull that out.

Thx


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[jclausen]

The gear your interested in is in the actuator assy you need to get it out and retake it apart

[RockOn]

Is there a way to bench test the motor? For actuation, spin the gear, etc.

I have it out now and want to bench test before I take it apart or order a new one.

I did pay $100 to Indy shop and he said that it failed all the tests but I don’t know what he actually did.

$1,100 to replace that with fluid change.
$1,400 for full salvage transfer case

Figured for a $150-200 part I’d try it.
No stranger to having the engine apart so....

Thx



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[RockOn]

So I took the motor off to look at the worm gear. Looks fine and seems to engage the gear in the right angle fine.

I can free spin the worm gear and also the larger gear that’s on the outside of the housing. When connected the combined assembly won’t spin at all.

Is this normal for the gear interaction?

So back to trying to bench test the motor.
Maybe (hopefully) the motor is just the only thing that’s shot.

Thx


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[RockOn]

Can’t get anyone to comment on bench testing the motor?

Again gears look ok.


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[RockOn]

So got a salvage yard TC w/actuator. Figured I’d try the easy first and just swapped the actuator (resistor from mine).

No luck and actually grinding was very loud/worst than before. Thinking since I reset the codes that the actuator was functioning and something inside the gear box is definitely
bad.

Codes came back plus I got two new codes (limp mode) and VGT calibration - this one probably from me trying to reset the VGT with the Foxwell.

Noise is definitely not good.

Next step is to swap the actuator back and replace the TC.

Thoughts? Suggestions.

Should the whole TC swap get me out of this jam?

Thx


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