DIS dead

[PAULF]

I've got a odd problem with the DIS on the wife's 1999 model B5.

I had it fixed for lines about a year ago, and last week she complained that there was no mpg display in the bottom half, but her amber washer warning still was on. I went out performed the push button test, switched the display on via the stalk, and came in all smug.

Two days ago, she said that the statistics had all been reset to zero, and we thought it may have been the garage it had been in and left it at that. She had another attack of DIS off, which she fixed by pressing the reset, so I just blamed her.

Today, it went off, and would not reset. It flashed on briefly once, with the stats at zero, and now the test gives nothing - not even the audio beeps! The rest of the dash works fine.

The last time we had DIS problems, it cost us dear -
2.5TDi tales of woe and fixes




so leaving it isn't an option. I assume a power fault somewhere.

I have had the dash out, and checked the three plugs - fine - and tried wiggling them - also nothing. I have had a quick poke about in general , but it looks like I'm going to have to do some electronauting.

Has anybody any ideas for a quick start, or the wiring diagrams for the dash/DIS? (I can't seem to get my Elsawin diagram reader to work on Windows 7 any more)

Thanks,

 

[PAULF]

Just an update
The reset switch was tested fine - it forms an earth when pressed, open circuit when not pressed.
I have now seen it come back on, and it goes though its' Power On Self Test sequence, so definite power supply issue. Live inputs appear ok.
A quick chat with ECU Testing confirmed the DIS display power supply comes from the dash internally, so return to them for warranty repair.

 

[Oranoco]

Happy days but no dials is a ******.

 

[PAULF]

Bum.
NFF by ECU testing, and they reworked the board to cover any dry joints.
Excellent turnaround service, but it's still not playing.

I think I need a bit more info on power inputs, just in case there is some strange issue with an input from the car.
When the unit comes back on, all the stats are reset too, so it is not like it is switched off, although as I said above, it does its POST and gives the amber 'OK' as if I have just switched it on
I've also tried giving the dash and connectors some wiggleage, but no joy!

 

[PAULF]

Bum twice over.

Had a chat with the engineer at ECU Testing, and he has said I'll need to send it back to them as it does seem like a board fault, but it may take a while to find the problem as they found nothing wrong.

At least they are dealing with the problem as well as I could expect.

 

[PAULF]

Could anybody confirm the power inputs on the three connectors into the dash please?

I've got ElsaWin pin assignment and wiring diagrams up, but the format is not the easiest to follow - Terminal 15, 58s etc take some deciphering.
I am most interested in where the power to the autocheck unit comes in.
I just have a niggling feeling that the fault could still be with the car, and a couple of hours work could well prevent weeks of no dashboard!

 

[PAULF]

Have now found Pin 7, Blue plug is open circuit - should be earth.

Does anybody know the location of the dash earth point (199 on the ElsaWin diagram), where (at least) the 3 earths from the blue plug come together?

It will save me hours of pulling wires if I get pointed in the right direction, and I'll need to check the connection for the security of the other ones.

 

[PAULF]

Anybody any clues?

 

[aragorn]

The earths are bolted on behind the kick plates in the footwell afaik.

 

[PAULF]

Thanks,
I found those ones last night and had a fiddle, but back to work today so couldn't go too far and wasn't sure if they were the correct ones.
The run in and home had it all working again, so further invest around there seems the way to go!

 

[PAULF]

Hmm,I'm back off work and still trying to diagnose this one.I've had the main battery earth off and cleaned up - it was ok with a reading of 0.3 ohms to the intake manifold, but thought I'd be safe.Had the earths off down in the footwell, but the dashboard did not die so there must be others. The brake light out warning is now flashing up randomly, and the stereo display had lines in it for a short time.I still think fiddling with the earths gave some repeat of the fault, but couldn't swear to it.I'm really struggling to find earthing point locations, so any help would be apreciated - ElsaWin just gives 'connection in dash panel harness' - with no locations!

 

[PAULF]

It looks like the 'connection in dash panel harness' is a splice in the loom itself. I've found two so far for earth wires, and expect at least one more.
I hope that I'll find something, as this is getting to be a pain!

 

[PAULF]

Can anybody(Aragorn or Der_Techniker maybe) confirm for me that Pin 7 on the blue plug is supposed to go straight to ground? Maybe Scott B5 can check with a meter if his dash is still out?
I have got most of the loom out from the footwell, and by removing the steering column, but I can't find any other splice for earth and I'm sure that Pin 7 should be a ground. It's annoying, as the ElsaWin diagram talks of earth connection 3 and I'm a bit boot-faced as I have only found the 2 splices!
For me to check further, I'll have to take out the centre console and the instrument panel structure - and I'm not keen on that! I can just splice in another ground point if it supposed to be earthed.
Again, some of this has been done with power on, and I still think I am triggering the fault randomly whilst pulling looms - although I still can't tell!
I'll try and post some pics at some point, to aid anybody else with this type of grief.

 

[PAULF]

Bum many times over.
I tried linking pin 7 to earth, and no joy. Due to the intermittent and changing nature of the fault, it is getting increasingly difficult to pin down any cause and effect!
I've now reset pin 7, and am looking for another dash to fit and try. (Wanted ad in Classifieds)
Car now all back together and I have a dim brake warning light on, that triggers the beep after a time, and may or may not clear. All stats are still resetting overnight!
If I get no success sourcing another dash, I'll have to leave it until we can do without the car for a couple of weeks whilst ECU Testing deep test it.

 

[PAULF]

Tried to add pics in context, but can't selectivley edit!
Here is the Pin 7,on the 32 pin blue plug

and the two earth connections I found

In case somebody else is searching for them!

 

[PAULF]

Thought I'd update this one a bit.
Over the winter, the faults came and went - sometimes a couple of weeks with no problem, then a day with no DIS, or the brake-light-bulb-out warning on.I often lost the time, average speed and MPG data without seeing any fault, so I assume it dropped in and out during the times the car was parked. The radio head unit also seemed to have a couple of blurry pixels sometimes, and I had a data coms. fault code for the radio on VCDS.
I finally found a dash insert that I was confident enough to fit - THANKS olds_kool (Kev) (it worked)

After setting it up, the new dash insert has performed fine for a couple of runs. I feel fairly confident, as the fault(s) were going through the O.N. mode of operation, so if it was a car issue, I'd expect it to have re-occured. Obviously it I can't be sure for a while, but feeling a bit more cheerful.
I'll have a chat with ECU Testing, who fixed it originally, as they said they would be happy to do some extensive testing and fixing under the 2 year warranty if I require.
I still think they have been very helpful and would recommend them - it's just that I couldn't give them the dash for an extended period to fault find.