75ZT Community

I have rather stupidly got involved today in trying to find why my mate's Hi-Line is not working in his late 2004 ZT-T and realise that I don't know where to start.

Only the LCD screen backlight is working, sometimes a white bar shows at the lower edge.
Television, radio and mutichanger modes are non-operative, satnav CD unit has been disconnected but that should not prevent the rest displaying, I believe.
The multichanger does load up after a battery off reset.

No indicators at all on the head unit. Fuse 33 intact, all connectors secure and no ingress of water to the spare wheel well but it is damp. Now I'm floundering.

Are there any common problems?
I've not been aware of reading about much trouble over the years.

If the TV unit is faulty and the sat nav is not connected I dont think you will get any graphics.
Without the sat nav connected you should get chunkier graphics and no sat nav option (blue screen I think)

Can you try any of the bits in one of your cars?

MN190 wrote:
Can you try any of the bits in one of your cars?

I was in the V8 today that has the new Chinese DD unit so nothing available to swap.

I will drag the V6 along tomorrow maybe as that still has the Hi-Line fitted.

I was under the impression that the SaNav unit is the 'brains' of the operation in so much that without it nothing else would operate... but I must admit I am a newbie in the HighLine lark too so don't take it from me as gospel.

Is the satnav unit faulty - is this why it is disconnected?

The symptom sounds like a missing kbus signal. When I first set my system up without the Kbus properly connected, I got black screen but I think the white menu bar at the bottom.

The main graphics device is the satnav computer, but all the video signals from this go into the TV tuner and back out before going to the screen at the front.

If the Satnav is dead, the TV tuner does as someone said, detect this and generate it's own menu which has naff looking graphics. However if the TV tuner dies, then the graphics from the satnav would not get through. The radio should still work, though, just no menu to control it with.

I dont think you get the white bar at the bottom with a missing kbus signal, only the back light shows, but definately worth checking. Was it factory fit or retrofit? A T4 (Testbook version 4.Computer Diagnostic System) would be able to speak to the Satnav unit but I don't actually know what would happen. I never had an error on mine for it to do anything.

Check if its damp that there hasn't been ingress of water and caused corroded pins, or there is anything touching down on the body work to ground. For every module not to be working is a little odd, the kbus would definately do that, but I can't remember what the screen shows, I use to forget to connect it all the time when I removed the headunit for any reason.

I think its had water / damp in which has fried the tuners
I would try swapping the TV tuners over first

Monk wrote:I dont think you get the white bar at the bottom with a missing kbus signal, only the back light shows, but definately worth checking. Was it factory fit or retrofit? A T4 would be able to speak to the Satnav unit but I don't actually know what would happen. I never had an error on mine for it to do anything.

Check if its damp that there hasn't been ingress of water and caused corroded pins, or there is anything touching down on the body work to ground. For every module not to be working is a little odd, the kbus would definately do that, but I can't remember what the screen shows, I use to forget to connect it all the time when I removed the headunit for any reason.

It may depend on the actual Kbus problem.

I had Kbus connected, but no instrument pack in the circuit. The IPK (Instrument pack (IPK from the German)) gives an ignition on signal on the kbus, and I think I had black screen, white bar when this was missing.

Substitution is the quickest, easiest test, but the TV tuner is not known for dying unless there's water about.

Thanks for the pointers.
So everything has to go through the TV unit for graphics unless overidden by the satnav graphics but is it (TV unit) responsible for the radio and CD system sound?

It used to be so easy to fault find the radio on cars, just 2 wires and an aerial in and two wires out.

The radio tuner is the sound amplifier for all components on hi line system.
If it has packed up normally caused by water ingress replace it with a straight swap BMW BM24 unit which has a far better sound and quality and has dual tuners so you will have permanent TMC working.
If units have been damaged by damp/water fix leaks first.
The TV tuner is best now replaced with a digital tuner or a straight replacement with the add on digital TV tuner to keep the signals working after switch off.
Also check all plugs sockets for corrosion and correct fitting.
Can end up an expensive update/repair.

John is right, Audio comes from the radio unit. However, the TV audio (obviously) and the satnav audio go into the radio from the TV tuner.

That means even with a dead TV and satnav, you should still get audio from the radio / tape and the buttons should work, even though there's no display.

To clarify exactly the relationship between the satnav and TV tuner graphics.

If it's all working correctly, the satnav produces all of the menus, sends it into the TV tuner which sends it straight back out, down to the LCD in the front. If you select TV, the TV module starts ignoring the graphics and everything coming in, and puts the TV picture out to the LCD. That's why the TV settings are all done when you are actually watching telly.

If the Satnav falls off kbus, the TV tuner detects this because it doesn't see the kbus messages. If this happens, it generates it's own menu screen, with satnav options missing, and sends these to the LCD ignoring any input from the satnav.

Proper digital BMW tuners are the nicest upgrade, but always been both arms, both legs, and a few internal organs in price when I've seen them. An external digital tuner works, but you keep the existing TV tuner and use it's aux video input by adding some wires, or buying an adaptor. Incidentally, you can also add a reversing camera to the TV tuner, but the video format has to be correct, though navcoder can switch it for you (yes Dave, I know).

Back to square one now.
Swapped out all the units today but no joy.
However, the speakers were live with the replacement radio unit even though the red indicator by the volume control is still not illuminated.

He's got the car back now, I expect he will leave the radio etc. as he has spent so much money on this car in the last year, you would not believe it.

Only one thing I'm still doubtfull about. Is there only one fuse involved for the whole setup?

Sorry, missed that point. Just read you'd cecked the fuses.

So, no, there are two fuses. One is the permanent feed, the other the ignition (accessory).

33 is the permanent, 11 is the ignition.

Bernard wrote:Back to square one now.
Swapped out all the units today but no joy.
However, the speakers were live with the replacement radio unit even though the red indicator by the volume control is still not illuminated.

He's got the car back now, I expect he will leave the radio etc. as he has spent so much money on this car in the last year, you would not believe it.

Only one thing I'm still doubtfull about. Is there only one fuse involved for the whole setup?

Did you try the TV and radio tuners in your car?

MN190 wrote:
Did you try the TV and radio tuners in your car?

No, I dug out the units that I took out of my V8 which now has the new Chinese head unit so too much trouble to put them back in just for testing.

I may have another go at it when my mate gets fed up with singing to himself for entertainment.

I am aware this is a very old thread but I would be very interested to know if this was ever fixed and if so how. I have almost exactly the same problem, a dead system with the back light working. The autochanger can be heard loading when powered up as can some whirrings from the satnnav. I replaced the TV tuner with a Hybrid but no change.

One of the common problems is a broken Kbus wire to either the TV tuner or the navigation unit. The kbus wire is the thin white / red / yellow wire. Because it's thin it breaks easily, but it can also be a join in the harness that fails.

I assume you don't have a flooded spare weel well which is another problem area.

DrFunk wrote:I am aware this is a very old thread but I would be very interested to know if this was ever fixed and if so how. I have almost exactly the same problem, a dead system with the back light working. The autochanger can be heard loading when powered up as can some whirrings from the satnnav. I replaced the TV tuner with a Hybrid but no change.

No, it was never fixed.
My spare units were all lost in a fire and the car in question suffered a further head gasket failure on the replacement engine that was fitted (190-V6). The car is now just used for the occasional 1/2 mile commute, during which time the engine doesn't get chance to blow much water. He has trashed this car by letting his son and daughter drive it, both well old enough to know better.

Thanks for the reply, though sorry to hear you had a fire and the subsequent trashing of the car!

I'm still only slightly further. The k-bus is not functioning in the part of the loom connecting the audio/satnav and tv units. I am currently thinking this could have it's origin in the instrument pack but am not at all sure if this is the cause.

Unlikely to be the instruments as lots of other things wouldn't work. The audio satnav and tv are all connected via the add in hi line loom, which connects to kbus down at the front under the head unit (colour screen). The wire is thin and might be broken between the wire and the plugs. You are looking for a large black multipin plug, with round pins. The wire is white / red / yellow.