Review: APR SCU (DSC Controller)

[Klrider44]

@Klrider44 Did you look at real time data with VCDS or OBD11 to confirm three modes?

And do you have a scan of your car? Some people have had hardware issues, but a lot of the issues seem to be software driven. Maybe you have the right combination of modules and software for error free operation... Maybe your car is exactly like the car that (we assume) they tested with.

I never did scan it.

 

[beanbag]

Update to say I called DSC to ask about their controller. They acknowledged that it does not "talk back" to the CANBUS, but that there was also a hardware change and that only early units gave error codes. Perhaps it is ok to buy one if they will allow an unconditional return if it does throw an error code. I don't know how the CANBUS system works, but why not attach BOTH the DSC and stock controller at the same time in a Y configuration - let the DSC one control the shocks, and the stock one "talk back" to the CANBUS system?

Edit: I also get the distinct impression that APR does not really know how to deal with this controller.

 

[scrllock]

Update to say I called DSC to ask about their controller. They acknowledged that it does not "talk back" to the CANBUS, but that there was also a hardware change and that only early units gave error codes. Perhaps it is ok to buy one if they will allow an unconditional return if it does throw an error code. I don't know how the CANBUS system works, but why not attach BOTH the DSC and stock controller at the same time in a Y configuration - let the DSC one control the shocks, and the stock one "talk back" to the CANBUS system?

Edit: I also get the distinct impression that APR does not really know how to deal with this controller.

the error codes were related to the traction control bug very early on. I very much doubt they fixed the gateway bug that causes problems with ECU flashing, headlight-level sensors, etc.

you cannot do what you're describing.

 

[beanbag]

The DSC guy mentioned a "level sensor error" that was fixed in the newer hardware, but I assumed he meant something related to the suspension, not the headlights.
Well whatever, all I want to know if it is going to cause errors or not.

 

[Cuzoe]

you cannot do what you're describing.

Let me start by saying I agree with this statement. I don't think it's practical, sensible, or advisable. But as a though experiment I do wonder if it's possible, given several considerations...

- Run separate power and ground to the DSC, no reason to complicate anything there.
- Can bus input is "tapped" into for every module on a given bus, so that's no big deal.
- For the level sensors and accelerometers the only thing that needs to be split is the return side
--- If you want the excitation (or power, if you will) side to be "driven" by both the DSC and stock controller you need some diodes in there to protect the outputs from each other
--- Adding these diodes a needless complication in my opinion
- That leaves only the output to the dampers
--- DSC damper output goes to the dampers
--- Stock module output goes to a set of DCC cancellers

Now this was typed while watching March Madness highlights, so it may be March Madness itself... what have I missed?

 

[scrllock]

Let me start by saying I agree with this statement. I don't think it's practical, sensible, or advisable. But as a though experiment I do wonder if it's possible, given several considerations...

- Run separate power and ground to the DSC, no reason to complicate anything there.
- Can bus input is "tapped" into for every module on a given bus, so that's no big deal.
- For the level sensors and accelerometers the only thing that needs to be split is the return side
--- If you want the excitation (or power, if you will) side to be "driven" by both the DSC and stock controller you need some diodes in there to protect the outputs from each other
--- Adding these diodes a needless complication in my opinion
- That leaves only the output to the dampers
--- DSC damper output goes to the dampers
--- Stock module output goes to a set of DCC cancellers

Now this was typed while watching March Madness highlights, so it may be March Madness itself... what have I missed?

that's not how canbus works, input and output aren't separate wires.

also the gateway will probably be even less happy with two modules responding than the DSC module doing a half-assed job at responding. the big reason to avoid the DSC controller is all of the random errors from other modules seeing weird canbus data--it's not just the ABS module (the original esc bug), the AFS module (the level sensor bug), it's also the steering module (steering wheel buttons going awol) and who knows what else I wasn't scanning when I had it.

The only reasonable application for this is in a racecar that's been stripped to the point of not needing most of the other modules (and presumably motorsport ABS), but at that point you're on 2-3+ way adjustable coilovers, not DCC bullshit.

 

[yakboyslim]

If they fixed the level sensor error they should advertise that. Considering how they handled things when I was talking to them I genuinely doubt they did though.

Still won't have three modes on most gateways though. Until it talks back on CANbus the gateway will still never request comfort.

 

[Cuzoe]

@scrllock I'm not in the least bit unfamiliar with how can bus works, haha. If the DSC module legitimately does not respond on the can bus, as DSC alleges, then there's no problem with allowing it to see can bus data by "tapping" into the CAN bus wiring.

Obviously this only works if the DSC module is truly just sniffing the bus. If it's responding at all this is a non-starter. From one scan someone posted elsewhere the DSC isn't reachable at any address the gateway is looking for. The car won't care about something sniffing the bus.

 

[yakboyslim]

@scrllock I'm not in the least bit unfamiliar with how can bus works, haha. If the DSC module legitimately does not respond on the can bus, as DSC alleges, then there's no problem with allowing it to see can bus data by "tapping" into the CAN bus wiring.

Obviously this only works if the DSC module is truly just sniffing the bus. If it's responding at all this is a non-starter. From one scan someone posted elsewhere the DSC isn't reachable at any address the gateway is looking for. The car won't care about something sniffing the bus.

The DSC definitely does something more than just sniff, because it somehow screws up the level sensor info getting to the headlights. Unless that data normally flows from sensor, to suspension module, then to the headlights. In which case that is just another symptom of it not talking on the bus.

 

[Cuzoe]

The DSC definitely does something more than just sniff, because it somehow screws up the level sensor info getting to the headlights. Unless that data normally flows from sensor, to suspension module, then to the headlights. In which case that is just another symptom of it not talking on the bus.

It seems VW actually did this in a few different ways. My car (DCC retrofit) doesn't have lighting package so rear level sensor goes straight to the DCC module.

The sensor can also be wired to the BCM. The AFS/lighting module (multi-function module in later vehicles, depending on package) and the DCC module, IIRC, can be coded to pull level data from the can bus instead of getting it directly.

I have the Erwin drawings from several cars, and several years of cars, but I would have to dig through them and look at the options to see exactly how many ways it can be done.

No reason the DCC module cannot have level sensor data directly and make it available over CAN bus though. Which would create the exact problem you're talking about for anything else that's looking for that data when the DSC is installed instead.

 

[yakboyslim]

It seems VW actually did this in a few different ways. My car (DCC retrofit) doesn't have lighting package so rear level sensor goes straight to the DCC module.

The sensor can also be wired to the BCM. The AFS/lighting module (multi-function module in later vehicles, depending on package) and the DCC module, IIRC, can be coded to pull level data from the can bus instead of getting it directly.

I have the Erwin drawings from several cars, and several years of cars, but I would have to dig through them and look at the options to see exactly how many ways it can be done.

No reason the DCC module cannot have level sensor data directly and make it available over CAN bus though. Which would create the exact problem you're talking about for anything else that's looking for that data when the DSC is installed instead.

I think it is a little more complex than "it is supposed to give the info to the headlights" because my car worked for a few before the headlight errors started.

Just weird all around, and I really don't see DSC/APR caring to fix it fully for all cases (I'd love to be wrong about that).

 

[Cuzoe]

I think it is a little more complex than "it is supposed to give the info to the headlights" because my car worked for a few before the headlight errors started.

Just weird all around, and I really don't see DSC/APR caring to fix it fully for all cases (I'd love to be wrong about that).

I would agree that it's not that simple. I would also agree that neither company is interested in fixing it. It's a really good idea with a bunch of other complexities that aren't directly related to the purpose of the DSC controller.

The only place I really see it working is someone with a base trim car (I guess somewhat like mine started) that retrofits adaptive dampers and tracks their car (so presumably has some/all of the nannies turned off). This person also has to feel that they can tune the adaptive dampers/springs of choice to perform as well as a dedicated track suspension. I don't know if that is or is not possible, I'm sure opinions will be divided, but maybe the person just likes to tinker .

I'm sure that I'll waste some more time looking into the feasibility of running the DSC along with the factory module. Again, ignoring the practicality of it, I just can't yet sleep with the prevailing notion that it's impossible.

Anybody got a DSC that I can buy for cheap, like really cheap, or pay to borrow for a while .