Hi All, Help please, apologies if this type of fault has been covered before, this is my first time posting here!

 

A few weeks back my Combi estate 4x4 2.0TDI late 2010, (220,000km), started having odd failure warnings on the dash at start up.

often the next time the vehicle started it would be all good, then it became more and more often, it now appears permanent.

The vehicle has had little and occasional use in recent weeks, and this seems to have deteriorated the situation.

Car starts and runs fine, all other systems apart from traction/abs is good, (that fault is a known wheel sensor which I am waiting for ever for parts to replace).

I have read many posts of headlamp mods and BCM fry ups, but mine are all std 55w halogens in dip and main.

Typically now I have no dip or main RHS, one indicator out at front and The opposite one at back, daytime running and/or fog lights no go, plus rear numberplate lamps no go.

wiring it tidy and original no dead bulbs or connector socket issues except for one day running lamp (which usually still works).

have checked all connections which look clean and tight, and have sprayed with electrical contact cleaner.

my main questions here are which is the best diagnostic scanner to use, will this also allow any necessary recoding if I need to replace the BCM? - I have avoided buying one up to now, but now is the time!

and;  is there a path to definitively identifying it as the faulty component e.g. a specific error code which would confirm this?

I am removing the BCM today to check connections etc I assume part number of the item I need will be on it possibly?

 

lastly is there any way around it as a new replacement? I will consider all suggestions, I have seen posts saying some electronics specialists may repair, but I have no idea who to go to over here, if there is a recommended repairer I may consider sending it for repairs.

 

thanks in advance, have a great day! 🙂 - Mark

VCDS.

Yes.

No one specific code, you have to interpret the information from all the fault codes.

Yes.

Edited 9 June, 20232 yr by J.R.

I had this problem and it was due to moisture around the BCM area. Leaving the doors and windows open on a dry day solved it and the problem has never returned. I found that switching on different things such as indicators would cause a different set of wrong lights on the display.

Have you had extensive rain lately? Maybe the interior is getting wet?

On 10/06/2023 at 02:27, pikpilot said:

I had this problem and it was due to moisture around the BCM area. Leaving the doors and windows open on a dry day solved it and the problem has never returned. I found that switching on different things such as indicators would cause a different set of wrong lights on the display.

Have you had extensive rain lately? Maybe the interior is getting wet?

Hi pikpilot, And thanks for that, it makes total sense, and yes it has been my suspicion all along, but currently we are not getting any dry weather, even with the sun out it is in the 90% humidity range often, I will examine the area further and see if WD40 helps, is pretty much constantly wet here now until spring, (august September). the situation is probably not helped by infrequent use currently.

Assuming you have Climate Control, if you do drive the car then make sure the aircon is ON. The humidity control is effectively seperate to the heating and cooling.

The incoming air first cooled by the aircon to condense out any excess moisture in the air. The cooled air is then passed to the heater system to raise the air to the temperature you have set on the display.

In the UK it is very effective in wet weather to stop the windows "steaming up" - that is say letting moisture in the air condense out on the windows. This is what the climate control does by condensing out excess water before feeding the air into the car.

 

Our cars have an energy efficient variable pump rate where the compressor is always being driven but power being used varies from near zero to max, determined by the control system

I leave my air con ON for 90% of the year and the difference in fuel consumption is only seen in the hottest of summer weather.

yep, air-con absolutely essential here, always used and mine is in good working order, issue not seen when vehicle in regular use, so standing in wet weather most likely, it has no garaging so out in the elements 24/7. maybe only used once a week or less recently.

could not find any damp in car interior yesterday, and as it was unusually dry and sunny had it open all day to airing started checking under dash area, all looked good all relays tested ok, all fuses ok cleaned and wd40'd all as I go, hopefully will get some time today to complete and I will post result.

Hi Again all,

I've tried all sorts of drying procedures with the car and the unit, and no changes  to the problem has occurred, It has taken me some time to locate a replacement BCM, but at last I have one . . . I'm just wondering what the process of fitting and setting this up is?, I have no problems physically removing the old and refitting the new, simple job, just wondering where I can get the VCDS coding software/hardware from and are there some guides as to how to set up the BCM?, can I fit the replacement and expect some improvements without it being coded to my vehicle? does the coding process involve entering the build options of the vehicle, or is it an intuitive software? - I have never used it before, thanks in anticipation