XDrive issues

[Jboyorak]

A few weeks ago I pulled my motor and trans, and after I reinstalled, my awd was not working. I changed my transfer case fluid at throw time as well. I have 4x4! Light, and have the following codes in my transfer case module

52D0 incremental encoder DIR- wire
52D2 incremental encoder IMP- wire
54C9 temperature sensor at actuator.

Connects seem good at the transfercase motor.

If anyone has any insight, it would be much appreciated. I'm almost at the point of throwing a different motor on there, but I'd rather be able to diagnose this properly.

 

[Twisted Tuning]

On the back on the T-case there is a little sensor. make sure you have that plugged in. And trace the wire to make sure its not broken anywhere. Do the same for the plug and wires that plug into the servo motor on the T-case.

 

[Jboyorak]

To follow up, I did trace and test all the wires from the module back to the motor. Everything seems good. Cleaned them up and still the same issue.

It is hard to find a diagram for the e90. I found one for the x3

Is the resistor the sensor? I can't find where what resistance it should be at.

I have a new one at my work I am going to attempt to test tomorrow.

Also, the temperature code, 54c9 always comes back after clearing, and it's present with the key in the on position. The other two only come on after after the car is started.

 

[Jboyorak]

In addition, I checked for resistance between the pins on both a new motor the old, both all seem to be identical. I tested the new motor's connector on the bench and the old one at the VGS module under the seat(at the other end of the transfer case motor's harness).

Both resistors (called a class resistor by bmw?) measured about the same. I am not sure if this is actually a temperature sensor.

The only other thing I can think of is maybe their is a short or issue from the transfer case's module to another module?

If anyone has a wiring diagram for the E90 xdrive system, that would be extremely helpful. It's to bad the Bentley manual does not cover this.

Edit: I also did try and plug in the new motor to see if the 54c9 code would go away. It did not.

 

[Jboyorak]

Found a diagram.

DIR, IMP and TEMP are all connected. Meaning at the motor they show resistance between all three. This may explain all three codes are coming up.

They all have connectivity up to the harness at the module. The module has power going into it(couple 12v, one oddly read 11v and a couple measuring 2.5v.)

I'm leaning towards a possible broken connection between connector 2 on the actuator and connector 2 on the resistor. If I'm looking at it correctly, they look like they should be tied together?

 

[Jboyorak]

Final update:

After I found the wiring diagram I was able to pin point the issue to the ground wire at the actuator. The wire broken off inside the connector, at the pin. Soldered a splice in and it works like a champ!

 

[doublespaces]

I wonder how that happened?

 

[Jboyorak]

I'm not sure. Perhaps It was pulled during removal.

Anyway, this website has a TON of wiring diagrams on it. I don't know if I would have been able to resolve this without one. I'm not sure if many know about it, but here it is!
www.bmw-planet.net/