Discover Pro Retrofit & Helix Subwoofer Problems!

[harryw999]

Hello, this is my first post here!



I've deleted all my other posts and decided to make a new one as well as posting on the forums for some advice...
So, my 2015 Golf R came with an MIB1 Composition Media, anyone who has one of these will understand why I want it gone (especially after paying so much for the car!)
I purchased an MIB1 Discover Pro kit - all of the functions seem to work apart from the driving modes (I read somewhere that this might happen and I never take my car out of race anyway so I'm not bothered!)




The issue is the sound. I have the Helix subwoofer in the boot (VW installed this, not me).
I have no sound. The only way for me to get sound is to turn on the infotainment system, unplug the subwoofer and plug it back in whilst the unit is on and the light on the subwoofer turns green and it functions. When it does function it sounds no where near as good either and I have to do this every time i turn on the radio!
Thinking it was just the head unit, I got hold of another Discover Pro (this time MIB2) and it has exactly the same problem. When I plug in the composition media back in the sound is perfect.
Can anyone suggest anything? The subwoofer is fine because it works with my composition media and the DP units are fine because they both have the same problem.

Also, do you know what that tiny hole is next to the status light? Is it a reset button?
Sorry for the long winded message!

Any help is greatly appreciated!

 

[beardedGTI]

This is a tough one to diagnose over the forum. Given that it does work fine on the composition, we can rule out the helix being defective. So then it sounds to me like the problem is in the wiring. Like there is something different in the wiring between comp and discover. I don’t have enough knowledge to say that is definitely it or what the difference might be. Maybe try to track down pinouts for both models and compare them?

 

[harryw999]

Thanks for your reply!
Yes, the Helix isn't faulty and the DP units clearly aren't either.

It's like the DSP in the sub has problems powering up. The status light will occasionally flash green but won't function until it's disconnected and reconnected.

I see where you're coming from with the different pin outs from the quadlock socket but they both seem to be identical but my knowledge isn't great at this either.

I was thinking that the DSP might need recoding - but can't really see this being the case either.

 

[beardedGTI]

I can’t say for sure whether the dsp needs recoding (as in we don’t know if it was ever coded properly in the first place). What I can say is that the intermittent connection would not be a coding issue. It should just work.

Is your eq and fader/balance on the head all set to zero? If so, and that doesn’t make any difference, can you reconnect the speaker harness directly into the head. Verify all speakers are working properly with the new head unit bypassing the helix.

 

[harryw999]

That's just it - It wouldn't surprise me if they hadn't even done it to begin with!
I agree, although when anything in the infotainment system resets (either hard reset or even just connecting to the 5F module in VCDS) the subwoofer will go off and will require disconnecting and reconnecting again.

As it's a brand new MIB2 unit, I also can't use the long coding helper in VCDS which sucks!

Everything is set to 0 but the bass is set to full!

To be honest, I wouldn't be 100% sure on how to bypass the helix as all the cables go to the DSP and don't want to break anything! I'm a noob. I presume all the wiring is correct as the composition media works fine and it works fine when reconnected (although as mentioned it doesn't sound as good!)

 

[beardedGTI]

Like I said, very hard to diagnose this online. My initial suscpicion is that it’s cable related. The helix is signal sensing so it only turns on when it gets a speaker signal. And when it does, you’re saying it doesn’t sound right. So there’s something wrong with the speaker signal it’s getting. We know the amp isn’t defective since it works with comp unit. It’s doubtful you have 2 bad discover units. But what we don’t know yet is how they sound stock and if they’re putting out a normal signal. Check this diagram, the first part only, and see if you can get the stock speaker connector back in the quad lock. The mission is to verify that the head and all speakers are working normally. https://goo.gl/images/BgSyEy

Also this doesn’t affect anything with your issue right now, but set everything including bass to zero. All eq and signal correction is handled in the helix. The head should be outputting a flat signal and nothing more. Again, not related to your problem at hand, just FYI.

 

[harryw999]

Thanks for the reply and thanks for the link! do you know what the red and brown wires are for? Are they not needed for the stock system?

 

[beardedGTI]

Only go by the first part of the diagram, the top pictures. You want to unplug the brown connector from the helix harness and plug it back into the quad lock. The second part, with the red and brown wires are power. You don’t need to mess with those.

 

[beardedGTI]

Actually this just donned on me: is it possible your discover units came from systems that had premium audio and you need to recode them to enable the speaker outs?
http://www.golfmk7.com/forums/showthread.php?t=29694

 

[harryw999]

Okay thanks, I'll give that a try tomorrow and report back!

Sadly not, I've coded it back to the internal amplifier and 8 channel passive speaker system in VCDS!

 

[harryw999]

Okay so the internal speakers seem to work fine!

Looks like all the issues are with the DSP then?

 

[beardedGTI]

Either the dsp or the cable. I’m thinking the cable might be crimped somewhere and the issue is intermittent or changes dependent upon position. The next step in troubleshooting for me would be to pull the cable out and test it just laying there. It that is a bit of work if you’re not familiar with installing the helix yourself. Is taking it back to the dealer and letting them sort it out an option?

 

[George Ab]

I would look at the settings of the 5F module on vagcom and compare to a known working unit. A known working unit would be someone with MIB2 non-Fender with a working Helix unit. You can go to Ross Tech retrofit section and ask for scans there, as that is what that forum section is specifically for. http://forums.ross-tech.com/forumdisplay.php?10-Retrofits There is also a section that provides reference scans, you may look for a 5F scan there that is applicable and compare to yours. http://forums.ross-tech.com/forumdisplay.php?45-Reference-Scans-and-Maps-of-Non-Broken-Cars

Also since the Helix worked with your original MIB1, hopefully you kept a copy of your 5F scan before doing the retrofit and can look for differences that would be applicable to your new MIB2 unit.

I will look over my scan when I get some time to see if there is any suspect areas to look at. A suspect area being one that would provide a wake up signal to Helix rather then forcing one by providing one manually as it appears you are doing.

On driving modes, yes the FeC which is associated with your VIN would need to be reinstalled.

 

[George Ab]

As it's a brand new MIB2 unit, I also can't use the long coding helper in VCDS which sucks!

I do not understand this statement. I updated my MIB1 to MIB2 and VCDS long coding helper works on both MIB1 and MIB2 units. See here: http://www.golfmk7.com/forums/showthread.php?t=31600 Are you using a hacked unit?

Since it worked with MIB1 unit, you may do a comparison between the old and the new and where there are changes look at long coding helper to see what differences are. For example if your MIB1 is coded to not work with the Fender system (47) and the new MIB2 is still coded for a Fender system, that would be where I would make a change and see if it corrects the problem. Below is only used for an example.

Current 027302000000000051220002001808001F0200F40120010002
Old 027300000000000021220002001800001F0203340100010002

 

[beardedGTI]

George, would this still be a coding issue? He says the stock speakers are working when plugged in and that’s the only thing helix needs.