[ImmBoo]

Hi,
I have a strange issue with the ACSM5 module in my BMW G30 2022. The car is reporting errors:

- 930959 - Active head-rest driver: Line connected incorrectly
- 93097D - Driver's side airbag: Line connected incorrectly

The car has 5500km and after checking the wiring harness, I didn't find any issues according to the diagram. Out of curiosity, I swapped the wires of the active headrest in the connector under the driver's seat, which didn't result in any changes in the errors. When disconnecting the connector under the driver's seat, errors appear as below.

- 930958 - Active head-rest driver: Resistance too high
- 930959 - Active head-rest driver: Line connected incorrectly
- 93097C - Driver's side airbag: Resistance too high
- 93097D - Driver's side airbag: Line connected incorrectly
- 9309C4 - Driver's seat belt buckle contact: Open circuit
- C95442 - No message (status backrest lock FA, 270.1.4), receiver ACSM, transmitter SMFA

Thinking that the ACSM5 module might be faulty, as suggested by ISTA, I replaced the module. However, after fitting and coding the new module, the same errors reappear. I coded the module using the original FA file without any changes regarding the factory equipment.

Has anyone encountered such a situation or would be able to assist in resolving this problem?

[Node]

Well, replace the rest of a car as already started with part cannon!

Now if you want to actually FIX this, then find where the wires going to head rest and airbag have too low resistance (could be a full short, but NOT necessary) between them and fix that spot.

P.S. I'm pretty SURE ISTA should have suggested this FIRST, before suggesting replacing ACSM!

P.P.S. Judging by SAME faults when connector under the seat is disconnected, the "short" is CLEARLY between ACSM and that connector (or inside that connector).

[Ratatouille98]

+1 with Node. Check wiring harness.
Could also be short to ground

[jaki]

So the car is very new. First question. what has been done to that car? Damage? or some "hifi" upgrade?
Usually simple things are the rigt ones
As previous posters say, probable someone have messed with some home installations etc.

[Simoniak]

Hi, did you check the plug and pins of acsm? Very offten water/moistour issues (flooded cars or even after "deep cleaning" carpets). Try to measure continuity between wires and check whole loom.
I strongly recommed you to dissconnect battery before doing anything with acsm. I you flip acsm unit with connected battery and igniton on every single airbag will blow!

[ImmBoo]

First of all, thank you for your suggestions. I must not have been clear enough - but as I mentioned, the harness has been checked for both shorts and damages. For testing purposes, even a section of the harness between the module and the seat was replaced, as well as the ACSM module (I have several of these modules, so swapping was very easy and quick with the center console removed).

However, the problem turned out to be more intriguing - when only the side airbag was connected to the module, all errors regarding improper connections disappeared. But when the wires from the active headrest were connected, both errors regarding improper connection for the active headrest and the side airbag appeared on the module. These errors couldn't be cleared even after disconnecting the headrest. Only a module restart or disconnecting the battery allowed clearing the error memory. After replacing the active headrest, there were no more errors.