DISCO3.CO.UK - View topic - D3 HSE MOST Help

Nasher

Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2697

2016 Discovery 4 3.0 TDV6 HSE Lux Auto Loire Blue

D3 HSE MOST Help

All

As per my other threads on here at the moment I’m currently experiencing issues with my 55 plate D3 HSE.

Following some water ingress – another story – I have no sound from my Radio or CD player, my parrot kit can’t connect to my phone, and the Sat Nav screen just displays ‘LAND ROVER’.
It did dry out and work for a while this morning, but has now stopped again.

The Head unit screen displays all the usual info, and reacts to changing to CD etc, but doesn’t display the volume when the knob is turned.

I suspect a MOST Loop problem.

With the radio and Sat Nav screen hanging out the dash and the ignition on I noticed a Red light inside the unit, and when I unclipped the MOST connector from the back of the Sat Nav screen there was a red light at the cable from the head unit. BUT, it went out almost immediately along with the Red light inside the head unit.
The Red light has now not reappeared through several cycles of the ignition.

Am I correct in thinking the Head unit generates the Light signal and is the beginning of the loop?

If so it’s no surprise that the Sat Nav screen won’t go past the ‘LAND ROVER’ Logo, and the Amp is not working, as it won't have a signal.

Disconnecting the MOST cable from the back of the head unit I can't see a red light coming out the back of the unit onto my finger behind the socket.

So, I'm assuming some water has got down inside the head unit, and although it worked for an hour this morning, coming back on line when everything dried out, it's now shot.

I’ve tried a Hard re-set, and clearing all the faults with my Nanocom.

I don’t understand why the parrot kit now won’t connect to my phone, I’d expect it to, but have no sound. When the whole system worked briefly after drying out this morning it did connect.

Can anyone comment on my ramblings above, and say if I’ve missed something.

I’m a bit concerned about splashing out on a used head unit without some more experienced comments.

Thanks

Nasher. Heaven doesn't want me, and hell is afraid I'll take over.

26th Nov 2016 6:55 pm

hgrimmett

Member Since: 11 Oct 2009
Location: Bledlow
Posts: 901

2015 Discovery 4 3.0 SDV6 SE Tech Auto Indus Silver

From my experience, all the units in the MOST loop generate a light signal and if any of the devices in the loop have lost power then the loop is interrupted and you get no sound from the radio. I don't think you have any choice but to check each component or build yourself a bypass cable and start a process of elimination? -------------------------------------------------------------------
D4 '15 (64) Se Tech Indus Silver
Tesla Model Y LR (22)
Audi TT Roadster 225 (52)
Tesla Model 3 LR (70) (gone)
Porsche Boxster '96 2.5 5spd project (P)
Mini R52 S (54)
BMW 330e eDrive MSport '16 (gone)
D3 '07 (56) XS TDV6 Buckingham Blue (gone)

26th Nov 2016 8:08 pm

Nasher

Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2697

Interesting.
So, the fact that I'm not getting a light out of either the Head unit or SatNav screen would suggest both are broken.

Or would the SatNav not send a signal if it doesn't get one from the Head unit?

Nasher Heaven doesn't want me, and hell is afraid I'll take over.

26th Nov 2016 8:21 pm

geoff.

Member Since: 24 Jan 2010
Location: West kent
Posts: 8531

nasher

u need to check you got power to the head unit first if it has but you've got no most signal coming out then you need to start with that

heres a most loop that will help

http://www.ebay.co.uk/itm/MOST-fiber-optic...Swa-dWlxLx

26th Nov 2016 8:25 pm

Nasher

Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2697

Geoff

Hi, and thanks.

I'll get a loop on order, but I think the Head unit is powering up as the screen on the front is showing all the correct information, Radio station etc, just not getting any light out the back.

Can you confirm that the Sat Nav screen would be putting out a signal even if it's not getting one from the Head unit? I've not got a light out the back of either at the moment.
It's getting power as it's displaying the Land Rover logo.

Thanks

Nasher. Heaven doesn't want me, and hell is afraid I'll take over.

26th Nov 2016 9:31 pm

Nasher

Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2697

After doing some reading up I’ve had another look this morning.

The head unit appears to be getting power.
The fuse is OK, I have 12V behind it, and with the ignition on or off the display shows everything except volume, and it mechanically plays CDs. But I do not have sound and the Sat Nav screen displays nothing but the LR logo.

So, unable to get a MOST loop today, Sunday, I disconnected the cable behind the Sat Nav screen and pulled the connector from the back of the Amp under the drivers seat. My 55 Plate HSE is not fitted with factory Hands Free so that’s not in the loop.

If the car is allowed to ‘go to sleep’, when you unlock the doors there IS a red light coming from the cable that’s plugged into the back of the head unit, and from the back of the Sat Nav screen.
However, there is NO light coming from the socket in the back of the Amp under the seat, which sort of suggests the issue is with the Amp which is nowhere near the water ingress.

BUT after @10seconds the Red Lights from the Head unit and Sat Nav screen go out, and will only reappear if the car is allowed to go to sleep again.

Would the MOST Loop shutdown like this if a fault is detected in the Loop?

When I manage to get a Loop, I’m assuming I can prove it’s the Amp by plugging the loop in at the Amp cable and I should have Audio-less Sat Nav and 4x4 screen – is this correct?

HELP!!!

Thanks

Nasher Heaven doesn't want me, and hell is afraid I'll take over.

27th Nov 2016 12:31 pm

Nasher

Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2697

Frustratingly stuck without a MOST loop now.

Have confirmed there's 12V going into the Amp, and that for 10 seconds after unlocking the car there is a light coming out of the disconnected cable at the back of the Amp that comes from the Sat Nav Screen.
But still no light down inside the socket on the back of the Amp, not even for the 10 seconds.
So the Amp isn't providing a signal.

For my peace of mind, and some chance of some sleep tonight, it would be nice to know if the MOST system would shut down after 10 seconds if it doesn't get a return through the loop.

Nasher Heaven doesn't want me, and hell is afraid I'll take over.

27th Nov 2016 2:29 pm

hgrimmett

Member Since: 11 Oct 2009
Location: Bledlow
Posts: 901

Yeah, I'm pretty sure mine did when my handsfree unit was faulty, it would make sense. -------------------------------------------------------------------
D4 '15 (64) Se Tech Indus Silver
Tesla Model Y LR (22)
Audi TT Roadster 225 (52)
Tesla Model 3 LR (70) (gone)
Porsche Boxster '96 2.5 5spd project (P)
Mini R52 S (54)
BMW 330e eDrive MSport '16 (gone)
D3 '07 (56) XS TDV6 Buckingham Blue (gone)

28th Nov 2016 5:15 pm

Nasher

Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2697

Thanks hgrimmett

Tried everywhere local this morning and couldn't find a loop anywhere.
Only one Car audio place even knew what a MOST Fibre Optic system was, so I've ordered one from ebay hoping it will arrive in the morning.

It's particularly frustrating as I'm off work today and tomorrow, but have to go back in on Wednesday for the rest of the week.

Nasher Heaven doesn't want me, and hell is afraid I'll take over.

Last edited by Nasher on 28th Nov 2016 6:00 pm. Edited 1 time in total

28th Nov 2016 5:54 pm

paulgriff

Member Since: 26 Jul 2016
Location: Balloch
Posts: 1

2008 Discovery 3 TDV6 GS Auto Bonatti Grey

Hi there,

Your head unit is the main module in the loop, this is the one that produces the infer red signal. it then in turn passes through the other modules in the loop (as long as the module wiring is ok and the module is in working order)

Your MOST ring is definitely broken, but by the the sounds of things the head unit is ok. The amp can be common on these, but if you have had water ingress further up makes sense starting there.

Once you get your MOST loop, you need to go round all the modules eliminating one by on until your screen starts working correctly or you get sound (depending which module is at fault)

Hope this helps

28th Nov 2016 5:56 pm

Nasher

Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2697

Paulgriff Hi.

As you sound as though you know what you're talking about

Do you know if it's normal for the system to shut down after @10 seconds if there is a fault?

It means I'll have to keep waiting for the car to go to sleep each time I move the Loop I suppose.

Thanks

Nasher Heaven doesn't want me, and hell is afraid I'll take over.

28th Nov 2016 6:02 pm

Nasher

Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2697

Update – some movement.

My frustration grows, partly because the MOST loop I ordered off ebay on Monday, and paid extra for 24hr Express delivery, hasn’t arrived yet.

Since Sunday:
I’ve had no sound at all from any system, not even a crackle.
The head unit screen showed everything except Volume.
The Head unit played CDs OK, but with NO Sound.
The SaT Nav screen showed nothing but the LR logo Constantly.
Unplugging the MOST Loop from the Sat Nav Screen showed a signal from the head unit plus a signal from the Sat Nav Screen.
Unplugging the MOST loop from the back of the AMP showed a signal light arriving from the Sat Nav Screen but no signal from the Amp.
When tested there was 12V going into the Amp at the main power connector.
My Parrot Hands Free could not connect to the car.

HOWEVER, bearing in mind it was very warm inside the car in the sun.
I’ve just popped out from work to get some lunch, when I started the car I noticed the Sat Nav screen had suddenly come to life and was showing cartography.
I’ve run through a few checks and found the following:
I have Fully functional Sat Nav – WITH SOUND.
I have fully functional 4x4 info screen.
I have fully functional CD playing WITH SOUND
I do NOT have any sound from the Radio.
The Head unit Screen now shows the Volume adjustment as well as everything else even in Radio mode.
My Parrot kit still cannot connect to the Car.

My first reaction is that it’s got to be the head unit, and the MOST loop I’ve got on the way can’t help me diagnose this.
Although I’ll try looping out the screen and Amp to see what happens.

Remember all this started when water from the roof dripped down over the Sat Nav Screen and Head unit, so despite the no signal from the Amp I’m inclined to believe it’s not that at fault.

Is the CD playing independent of the MOST loop? - If so it could be bypassing the Sat Nav Screen.
Does the Radio and CD use different channels in the Amp?

Can anyone who knows about these things be able to comment before I pay for a used Head unit?

Thanks

Nasher. Heaven doesn't want me, and hell is afraid I'll take over.

30th Nov 2016 3:01 pm

Nasher

Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2697

Looks like I’m out on my own with this one.

I still have everything working except sound in Radio mode, so am listening to CDs I’ve not heard in a while.
I’m obviously concerned though that with temperature cycling etc the circuitry for rest having been damaged may well go down again.

Thanks to a loan from a colleague at works friend I’ve swapped in a ‘known to be good’ Amp and it didn’t make any difference.

I looped out the Amp, and lost all sound, which was obviously not a surprise.

Looping out the Sat Nav Screen obviously lost me all functionality of the screen, but also as expected didn’t give me back sound in Radio mode.

So it’s all pointing at the Head unit, and thanks to another member on here it looks like I’ll be sorted with one soon.

Nasher. Heaven doesn't want me, and hell is afraid I'll take over.

5th Dec 2016 10:29 am

jeep948

Member Since: 16 Feb 2017
Location: Kelso
Posts: 200

2007 Discovery 3 TDV6 SE Auto Bonatti Grey

Hi, Did your new head unit resolve your issue? Having a similar issue with mine although the only other fault I can see apart from no sound is that the phone cannot be picked up when searched for. Thanks

16th Feb 2017 1:47 am

jeep948

Member Since: 16 Feb 2017
Location: Kelso
Posts: 200

Help with Faulty Sound system

Could anyone give me a bit of advice on where to go with this issue?
I have checked all connections are in tight etc, no broken wires that I can see, had the head unit out of the dash....
Looked for water ingress but everything seems fine and dry.
It does not pick up the phone when I search for it on my iPhone, it says Phone not connected@ so assuming no Bluetooth kit fitted???
The sound comes on randomly when driving and stays on until you park up & then nothing when you get back in the car later on.
I don't really want to change the CD Player if its not at fault.
I would appreciate some help on this one!

Thanks in Advance.

23rd Feb 2017 10:05 am