Dead Display

[Steveijc]

I'm new here but have been a lurker for some time! Wonder if anyone can help with my problem. I have a 99 b5 1.8 SE non turbo with the full dis. It occasionally throws a fit and beeps numerous times on and off during a journey but most of the time, it's on OK and the pixels aren't too bad. The past week however, it's been off altogether. No amount of fiddling with the stalk/reset etc will make it come to life. I've checked the fuses and connections on the back and all seem tight and ok. I've found numerous threads about failing pixels but none where the dis goes off altogether, no back lights etc. I'm wondering if there is anything else I can do to see if I can make it work, it's a big miss not knowing how many miles are left in the tank etc, outside temp etc. I don't have VAG-COM or anything like that. The rest of the instrument panel is fine, just the DIS.

Thanks in advance to anyone who can offer help.

 

[MaverickTDi]

I too have this problem on my SE non-turbo. Well when I say problem the pixels fade away and I can't see any info. Having watched a DIS screen replacement on YouTube, the LCD screen is the 'ribbon' type and it can deteriorate over time which induces faults. The replacement itself seems pretty straight forward if you have a steady hand! Take your instrument cluster out and check the PCB joints and solder tracks, could have a dry joint or lifted track?

 

[aragorn]

Thers two different issues here.

Fading with heat and missing pixels is an issue with the ribbon cable on the LCD, and usually neccesitates an LCD replacement.

Thats a different issue to what the OP describes though.

Steve: Can you tell us if the backlight on the display is on, ie is it red with no writing, or is it completely black?

Also have you run the fuel down (or screenwash) and got the little yellow warning to appear in the DIS to say your low on fuel? If not, try unplugging the sensor underneath the coolant reservoir and start the engine and see if you get any warnings in the DIS.

Its possible to turn the dis off, by pressing the button underneath the stalk. If you turn it off, all the warnings i mention above still work normally. If those warnings still work, but pressing the button doesnt turn it back on, then i'd be looking at a fault with the stalk or perhaps its wiring.

 

[Steveijc]

Hi there! Thanks for the replies. The pixels were fine prior to this, maybe a couple of lines missing but still readable. Now it's as if the whole thing has failed altogether. I'd had the brake pad warning on for as long as I can remember, pads were fine so always ignored it. There is no backlight on the dis now, just a black screen with nothing at all displayed, as if the ignition is switched off. I used to be able to switch the screen off and on with the stalk but the pad warning always remained on, but now that's not the case. The rest of the cluster gauges and mileage etc still works perfectly.

 

[aragorn]

sounds like the cluster is broken then, might be worth grabbing a spare from scrap yard and swapping it over.

 

[Steveijc]

Would this be a straightforward plug in and go job if I found the same kind of cluster with the analog clock, or would it require coding by a specialist? I can live with the mileage being wrong if it meant I could bung it straight in. Are the clusters known for failing totally on the B5? Seems plausible although I feel unlucky. I'd rather be one of the many with the dodgy pixels!

 

[MaverickTDi]

As far as I'm aware they should be a straight forward swap. IIRC there's 3 electrical connectors at the back of the cluster, simply disconnect and reconnect to your new cluster. There will be no coding required as it just displays info from various sensors on the car.

I've owned 2 b5's now and my only experience is the degrading pixels on the LCD screen. I've never heard of the issue you have?

 

[aragorn]

The cluster includes the immobiliser, so yes, it'll need some coding done to get the car to run.

However, you can simply plug it in and see if the LCD works. If it does, you know the old cluster is faulty and can spend the money on getting the IMMO coded in (either buying the cable to do it yourself, or paying someone). If it doesnt, theres some other fault you can try to chase down.

 

[MaverickTDi]

The cluster includes the immobiliser, so yes, it'll need some coding done to get the car to run.

However, you can simply plug it in and see if the LCD works. If it does, you know the old cluster is faulty and can spend the money on getting the IMMO coded in (either buying the cable to do it yourself, or paying someone). If it doesnt, theres some other fault you can try to chase down.

Fair enough I stand corrected.

 

[Steveijc]

It's a bit of a 'running on a shoestring' car so I'm reluctant to take it to an auto spark. I might try a scrap cluster if I can get hold of one and see if the dis works. I kind of wish the car never had one now and just had the bog standard seperate warning lights! I'm not well up on electrics but I would have thought that the fuse should blow before the dis does?

 

[MaverickTDi]

It's a bit of a 'running on a shoestring' car so I'm reluctant to take it to an auto spark. I might try a scrap cluster if I can get hold of one and see if the dis works. I kind of wish the car never had one now and just had the bog standard seperate warning lights! I'm not well up on electrics but I would have thought that the fuse should blow before the dis does?

I think Aragorn's advice is best, get a scrap cluster and see what happens. You'll probably find there isn't a fuse just for the DIS hence why you've found no blown fuse. Using a multimeter you'll probably find power is still getting to the DIS it's just completely failed.

 

[aragorn]

Think of the dash cluster sort of like a computer. Theres a microcontroller on the board which runs all the guages and also runs the DIS. Its rare, but stuff can go wrong with it. Even the seperate warning lights are still run by the same microcontroller. These cars are old now, so its not unsurprising things can go wrong, but they're usually plentyful in scrappys, parts are cheap and theres plenty knowledge around to sort it out.

If your getting a spare cluster, bear in mind there are three generations. The cluster must come from the same type. Your car is the middle type, and you need a cluster from a 98 or 99 car most likely. Easiest thing to do is match the clock. If the clock looks exactly the same, its the right part.

Its not huge money to get it coded, but you need to go to the right places. Some places charge a fortune, others are much more reasonable. Or you can buy the leads on ebay, they're knockoffs but usually work alright. Other option is to find someone on the forum with the leads that happens to be local to you. If your near me i'll sort it for nowt.

 

[Steveijc]

Thanks aragorn, the explanation has helped me understand it better now. You're right about the clock, it's the non digital version with the oil and battery gauges. The car has the single piece headlights and the corroded metal boot strip, so I'm guessing it was one of the early versions of the final facelift as it's a 99 'T'.

Your offer to sort it was very much appreciated, especially as I'm a newbie. Alas, I'm down in Geordieland, but it's nice to know people are willing to help.

I might have another twiddle with the wiring tomorrow in daylight. Does anyone know where the plugs on the back of the cluster actually lead? Is it through the bulkhead straight to the ECU? As a final check before I seek a new cluster, I might check to see if theres a plug thats become detatched at the other end.

 

[aragorn]

The plugs just disappear into the main wiring harness then snake off all round the car. Theres no "other end" as such.