DSC

[Tom Holland]

Hello all, Would greatly appreciate any help on this. I bought a Z3 with the DSC light on (smart move I know)
So I changed the yaw sencor and it made no difference. An auto electrician told me when not connected it was reading 3.5 g, he checked the wiring. OK and suggested it was the Abs module causing the problem. So I bought another from a breakers yard off a series 3. ( This was to match part numbers) So now I'm being told that if Its fitted it may have to be match coded with the chassis number and that's... Difficult. I would need to get the Ecu re-mapped? I'm sure other people have had this problem. Will it be the same for the yaw sencor I fitted or in future ie vanos unit? Thanks for anybody help. Cheers

 

[mrscalex]

Your start point (and it's not too late now) would have been to put a code reader on it. Or did you do this already to diagnose the yaw sensor? If not you could be barking up the wrong tree with the module & yaw sensor. Personally I wouldn't trust what an auto electrician told me.

Nothing wrong with a module off another BMW as long as the part number matches. But strictly speaking it should be recoded so the module knows exactly what configuration it's controlling, ie you'll never know if a critical parameter not changed may affect the control when you most need it. It's not the ECU (DME) that needs to be recoded. It's the DSC module. VANOS nothing to do with anything.

There's a good chance it will extinguish the light okay. But it if the donor car had a component your car doesn't the module will complain anyway when it doesn't find it (and vice versa). This is more true of the SRS system, eg side air bags on donor car. And not on your car. But you never know.

If you can find a trustworthy independent BMW specialist (BMW dealer very unlikely to touch it) you would expect to pay anywhere between £35 to £150 depending on how pricey they are. It's a simple job for them. Well I've only ever done coding on ASC units and that's simple but I can't believe the DSC is any different.

 

[Tom Holland]

Thank you Mr scale, when I bought the car I pointed out the DSC light as I had problems on a previous z3. The owner told me that her mechanic had the fault codes saying yaw sencor as did (I'm told a BMW dealership garage in Bristol.) My mechanics snap on diagnostic gave a fault codes suggesting yaw sencor. As did the auto electrician. So the Abs module has not yet been fitted because I'm in a dilemma. A different garage has suggested we just connect it without opening the brake lines and see what it does first. It could be the abs module is working and just the control box can be swapped which I think I saw in a forum. Then I could use the donor and send original for refurbishment and replace later. Thus avoiding coding issues, or as you mentioned. The example of the vanos was just as an example. Either way it will get done properly but for now it's booked in to try finding the solution. I see zsheds mentioned in posts, are they groups of friends or like mystical spirits you can call on? Thanks again for you assistance, much appreciated.

 

[mrscalex]

The unit has a wet and dry part. The wet part is the pump and it rarely malfunctions. The dry part is the module and frequently goes wrong. Though the DSC is much more reliable than the ASC in my view. Never, ever bother with the pump unless you are convinced that’s what it is. It’s nearly always the module. A simple physical swap. Recoding simple enough if you know how or know someone who can. Sending for repair is in my view expensive for what it is but it does mean recoding is avoided.

 

[Tom Holland]

Good morning, sounds like I'm on the right track. Thanks for the advice. Do you know anyone that can fix an ASC. Have I got this Zshed idea right? It's a group of friends that help out each other?
Regards Tom

 

[Nodzed]

Hi Tom, are you based in Bristol? If so you are welcome to come over to Zedshed West (Lydney) and we can ask @colb (Colin) if he can come and stick his laptop on it for you, OR see see if you can arrange a visit straight to him.

 

[Tom Holland]

Hello Nodzed, no I'm in the NW but would be happy to drive to Bristol for some help. I have car booked in at a new garage for me as I described next week. Let's see if this Module swap works. If not maybe I can drive down.

 

[Tom Holland]

Hello again, or maybe I could drive down and you can tell me what's wrong so I don't need to go to the garage or at least know what the fault is. Is that possible?

 

[mrscalex]

Hello again, or maybe I could drive down and you can tell me what's wrong so I don't need to go to the garage or at least know what the fault is. Is that possible?

This sort of stuff is not within the range of the average garage. If they are not specialist or if they are not experienced and are just offering to have a go I wouldn't bother. You'll be paying for their learning time with no guarantee of a result. Or for them to add their margin if they sub it to a specialist. If they want to do it on a no fix no charge basis maybe consider it but if they don't code it/code it properly they haven't done the job. And you'll have no way of knowing as long as the light goes out. Anyone can just physically swap a module.

You've got a long drive down there but I would consider it. Talk to @colb first to make sure he's happy to have a go. I've done several ASC modules now. Not done a DSC but can't imagine they are any different. Swapping the module and re-coding (ASC anyway) is 30 mins if you know what you're doing. The easiest tool is NCS Expert. If you like your computers and fiddling you could even have a go yourself. There are documented procedures (pretty brief) for ASC and as I say, DSC should be very similar.

 

[mrscalex]

All this assumes it is the module at fault by the way.

 

[Tom Holland]

Yes and this is my problem, supposedly previous owners mechanic and a BMW garage said it was the yaw sencor. Usually fails due to water. My roof leaked badly, carpets soaked through. Changed yaw sencor for another(is it good / is it still bad?) one mechanic tells me he must swap over DSC and ACS together. Owners with experience like yourself say it can be split. I'm going with you and Nodzed advice.

 

[Tom Holland]

This sort of stuff is not within the range of the average garage. If they are not specialist or if they are not experienced and are just offering to have a go I wouldn't bother. You'll be paying for their learning time with no guarantee of a result. Or for them to add their margin if they sub it to a specialist. If they want to do it on a no fix no charge basis maybe consider it but if they don't code it/code it properly they haven't done the job. And you'll have no way of knowing as long as the light goes out. Anyone can just physically swap a module.

You've got a long drive down there but I would consider it. Talk to @colb first to make sure he's happy to have a go. I've done several ASC modules now. Not done a DSC but can't imagine they are any different. Swapping the module and re-coding (ASC anyway) is 30 mins if you know what you're doing. The easiest tool is NCS Expert. If you like your computers and fiddling you could even have a go yourself. There are documented procedures (pretty brief) for ASC and as I say, DSC should be very similar.

Hello again, the drive is not a problem, that's the fun part. Also be glad to meet some enthusiasts. I will try to contact Colin as its his decision.

 

[mrscalex]

It's true the yaw sensor and acceleration sensor sit on the floor pan and can be affected by leaks. But plenty of Z3s have leaks and do not get affected. You have to go by the error codes rather than making an assumption.

ASC 100% certainty you can swap module only. DSC never done one but can't see it would be any different. You have one system or the other. It's the pump and plumbing that don't usually need touching.

 

[mrscalex]

I'm only down the road in Swindon. But I'm sure colb can sort you out. If not you can always swing by here after if I know you're coming. The proviso as you know is I've done ASC several times but not DSC.

In the meantime I will look at a DSC car and make sure the access to remove the module is good. It's on the other side of the engine bay to the ASC in a very different position.

 

[Tom Holland]

I'm only down the road in Swindon. But I'm sure colb can sort you out. If not you can always swing by here after if I know you're coming. The proviso as you know is I've done ASC several times but not DSC.

In the meantime I will look at a DSC car and make sure the access to remove the module is good. It's on the other side of the engine bay to the ASC in a very different position.

Thank you Mrscalex, I have just sent @colb a message let's see what he says. Maybe I could swing by anyway. I have other questions about car, like is it needing bushes and is car worth it. I love it but I think I bought an ongoing project.....

 

[Mario]

I've fixed three cars with a similar problem either the yaw or the rotation sensor get wet and need to be replaced, I can't remember which one, I believe it's the yaw sensor from memory - you need to go into the DSC ECU with the right software (DIS etc) and with the car on level surface and stopped tell the DSC to relearn the "ZERO" position then test the car, that is necessary otherwise it will read with an "offset" and give errors unless you initialise - as different sensors will have different "Zero" points even though its the same part number. I've never seen a DSC module failed yet but if you need one I have a replacement one I could offer to you for a reasonable price, still you will have to get that module to learn your sensors too and in that case both the steering wheel position sensor as well as the lateral acceleration sensor.

 

[Tom Holland]

Thank you Mario, I appreciate it. Cheers Tom

 

[Tom Holland]

I'm only down the road in Swindon. But I'm sure colb can sort you out. If not you can always swing by here after if I know you're coming. The proviso as you know is I've done ASC several times but not DSC.

In the meantime I will look at a DSC car and make sure the access to remove the module is good. It's on the other side of the engine bay to the ASC in a very different position.

 

[Tom Holland]

Can I take you up on your offer to look at my car?

 

[Tom Holland]

Good morning all, thought I might drop a photo or two of the position on my car of this DSC ASC unit. I can reach all of the torx and the plug. Sorry to sound a complete numpty but the DSC is the cylinder and black box? The ASC is the wet part the pump?