Do headlamp washer functionality involve a specific BCM?

[Go4IT]

Hi there,
i've recently retrofittet Xenons to a facelift MK4, and also the headlamp washers. The pump itself is working if pulled to ground on pin 10 of the green BCM plug and also CCC hast changed to "With headlamp washer", but it still don't work. The last thing comes into my mind was that there may be a special BCM model needed and the one in the car simply does not had the Mosfet equiped for this? A little bit like the TMPS antenna parts missing in most BCMs.
Any thoughts on this?

[ZvonimirG]

This is what says on Etis

There are three levels of equipment.
Low medium and high, so it is possible that BCM don't have output for headlamp washer.
Usaly there is sticker on BCM with info of level BCM

Headlamp washer system

The headlamp washer system will start to operate when the windshield washer function is activated if, at the same time, the light switch is set to "dipped beam" or the headlamps have been switched on by the "automatic headlamps" function. Electrical control is performed by the headlamp washer system relay which itself is controlled by the generic electronic module (GEM).

In order to prevent excessive water consumption, the headlamp washer system is only activated every fourth time the windshield wash/wipe switch is operated, provided the time elapsed since the first operation of the headlamp washer system does not exceed 10 minutes. If the windshield wash/wipe switch is activated again after 10 minutes the headlamp washer system is activated and the time encoder is restarted.

If the wash water level warning lamp on the instrument cluster comes on because the wash water level in the washer reservoir is too low then the headlamp washer pump is no longer activated until the washer reservoir is topped up.

[Go4IT]

Sounds good @nutra! Where can i find that sticker you mentioned, resp. what could be the indicator for LOW, MID, HI?
Here some examples of FL BCM labels:

bcm_label3.jpg

bcm_label1.jpg

bcm_label2.jpg

bcm_label4.jpg

bcm_label6.png

[ZvonimirG]

Here I don't see such designation like on older BCM, but from Parts cataloge BCM is offered only in high level so for all benzin motors and 1.6, 1.8, 2.0 tdci is BG9T-14A073-CM and only for 2.2 tdci is BG9T-14A073-YM

[Go4IT]

Thank you very much nutra! I also know that only 2.2 Diesel is different from BCM HW/FW and all others use the "same" version. So this fits perfectly.
Could it be that the HW-Version "-A*" is for LOW, "-B*" for MID and "-C*" for HIGH line?
C-Models are a bit hard to find for a good price, but B-models are more available.

[Go4IT]

I found somebody selling a BG9T-14A073-BM (from a 2011 Galaxy) and he said the car got Xenons, so this seems right for me and maybe a proof for my theory that B-models are MID....

[Go4IT]

Here is what i found out with A model:

see the diffs between my 2.2 Diesel Y-Model and a 2.0 Diesel A-Model:

diff_BG9T-14A073-AD_BG9T-14A073-YD_pcb_top.png

Headlamp washer pin goes to this IC:

st_0938552_swra.jpg

IC (STMicro 0938552) is only available in China and there are maybe more parts involved for the function.

12-07-_2021_08-19-27.png

[ZvonimirG]

Thank you very much nutra! I also know that only 2.2 Diesel is different from BCM HW/FW and all others use the "same" version. So this fits perfectly.
Could it be that the HW-Version "-A*" is for LOW, "-B*" for MID and "-C*" for HIGH line?
C-Models are a bit hard to find for a good price, but B-models are more available.

That is highly possible to be A low B mid and C high
When I have mk4 in service I will look wich bcm is present regardless of equipment

[ZvonimirG]

There is also AG9T-14A073-ED

IMG_20210712_163124.jpg

IMG_20210712_165057.jpg

IMG_20210712_165104.jpg

We replace it with BG9T-14A073-CL under warranty

IMG_20210712_163134.jpg

[Go4IT]

As you see, the AG9T-..-ED is missing for the parts also.