E93 - Driver's Window Switchpack Nonfunctional Experiencing Frustration with This Matter

[Geek2232]

I have been contending with challenges lately, and these challenges have manifested as wires. The master window switchpack of my E93 has become inoperative, and I am unable to determine the cause. Here is a comprehensive account of my completed tasks to date.

Context


The former owner brought it to a repair shop. They identified a "failed switchpack" but did not replace it.
I have subsequently replaced and recoded the FRM independently. Only modified the VIN and UIF information. The interior lights are functioning correctly; however, the window issue remains unresolved.


What Effectively Functions

All four windows function flawlessly from:
The button for the convertible roof
My scanner and diagnostics

The FRM can manoeuvre all the windows effortlessly.


Malfunction Codes

9CBA – LIN operator unit disrupted
9CC4 – Disruption in passenger mirror LIN
9CC3 – Disruption in driver mirror LIN

These remain unchanged regardless of whether the switchpack is connected or disconnected.

Electrical Inspections

The power and ground at the switchpack are accurate.
12V on Pin 6 (Red/Green).
Ground connection on Pin 5 (Brown).
LIN bus is located on Pin 4 (White/Brown).
The presence of 12V and ground at their respective locations indicates that the problem does not lie between the FRM and the switchpack for those circuits.
LIN also attains the switchpack plug at approximately 9-10 volts.


Unusual Ground Behaviour

The door is open; the ground measures approximately 40Ω to the metal in the fuse box.
Door closed: resistance decreases to approximately 3Ω.
With a jumper: 1.5 ohms.
Enhancing the grounding did not restore functionality to the switchpack.


Additional Remarks

All fuses are functioning properly.
No apparent damage in the door loom.
The mirrors are also inoperative due to the switchpack, which is logical as they utilise the same LIN line.

My Current Location

The FRM can operate all functions, however the switchpack lacks bidirectional communication.
LIN errors persist even when the switchpack is disconnected.
All indications suggest either:
An inferior switchpack,
Or something upstream on the
LIN line is impeding communication.

I welcome any insights from those who have encountered this specific demon previously.
I appreciate your assistance in advance.

[WiseSage]

It appears you have conducted comprehensive diagnostics, commendable effort. The FRM's functionality indicates that the switchpack is either nonfunctional or that a problem on the LIN line is disrupting communication. I would tend to suspect a defective switchpack, particularly given that the LIN problems persist even when disconnected. It is hoped that an individual who has confronted this specific E93 issue can provide a conclusive solution. Best of luck, and please keep us informed.

[Geek2232]

I am contemplating this; but, I prefer not to expend the funds without unequivocally verifying that this is the problem. I purchased an inexpensive imitation on Amazon for approximately £10, and it did not resolve the problem. I may require an additional OEM unit. However, my lord, these demons, gremlins, and magical wizards are indeed resisting vigorously.

[IrvesBMW]

Hello, I have encountered similar issues previously. I must assert that the switch packs on E90 models are often quite reliable, therefore I personally doubt that this is the reason. CAN bus systems are quite problematic, as they are dispersed throughout the vehicle and are easily disrupted by moisture. Begin by disconnecting the harness from the driver's door; there is an 8mm bolt on the vehicle's body side, after which you may detach and unplug the multi-plug. Inspect for moisture, visible corrosion, etc. If it is a connectivity issue, a thorough cleaning and manipulation may suffice. If acceptable, I will likely examine the harness behind the door panel. To proceed correctly, a wiring diagram is essential; nonetheless, these prevalent concerns may suffice! Best of luck

[Geek2232]

I have disassembled the connector within the door and removed the door card. I have examined the wiring from the switch pack plug to the frm, and all the wires appear to be in satisfactory condition. No rusting whatsoever.
While it is possible that there may be some damaged wires at some point, I am truly struggling to locate them!
 

[drummer]

To my recollection, there exists a splice beneath the carpet where multiple bus line cables converge, which was susceptible to moisture problems.

[Geek2232]

Beneath the carpet on the driver's side? That is one location I have not examined. I only presumed that all processes concluded at the FRM.

[IrvesBMW]

Indeed, you have initiated progress! As I mentioned, acquiring quality wiring diagrams is essential, although they are more difficult to obtain in the present day. The subsequent steps will involve verifying continuity and voltages, which is somewhat time-consuming. It is advisable to inspect the passenger side in the same manner as the driver's side, as the CAN bus also operates on that side. If it fails, it will affect the entire system. I shall continue to contemplate.