Dot Matrix Messages, Doesn't seem to display much...

[Ciaran]

Evening guys,

Not meaning to invent more work, but I had a realisation today. The dot matrix in my S2 doesn't seem to say much aside from the radio station name, and Door / Boot Open.

In comparison to the S1 display, which warns about ABS out of use, low hydraulic pressure when starting, auto / sport suspension, etc, the S2 does none of this. Can anyone think of any reason for that?

I realise that they removed some stuff like 'Stop lamp test' etc between S1-S2, however surely the more important warnings are still there. Indeed, a few times in the S2 I've had the low coolant level light on, or the ABS, and the dot matrix says nothing about it. It never beeps either.

I appreciate this problem is a bit random to say the least, but was wondering if anyone could even hazard a guess as to the cause? Its a bit of a puzzler!

Cheers

Ciarán

[xmexclusive]

Hi Ciaran

I seem to rember that your series 2 is a conversion from 2.0 petrol to 2.1 TD and they may well have tried to make the best of the available wiring connections. The wiring looms are different and I very much doubt they swapped them. There may even be dash display differences as that is the case with the RH dash displays. Not easy to track down as you need to determine if the problems are in the wiring, the display or a combination of both. Trying your display in a known good Mk2 2.1 might be a good first step.

Regards

XMexc

[Ciaran]

Hi (again ) XMexc,

Good point, I can't believe I forgot about the whole engine conversion thing! I think you're right on the money with your diagnosis too, its the only thing that makes sense, as everything else about the display works.

I may have to try obtaining a spare display and seeing if that makes any difference, I'm leaning towards the wiring though.

One thing, and I don't know if this has any bearing, but I did once see the display show warnings about other stuff, I had the car up on ramps, and attempted to start it with the battery extremely low. The engine turned over a few feeble times and predictably stopped. The rev counter (which doesn't work), and speedo both shot up to maximum, and the dot matrix beeped (the only time ive ever heard it beep), and displayed a series of 'Hydraulic pressure', 'Engine temp', 'Engine oil pressure' messages.
I'm not sure what this proves. I wonder did the low battery voltage just cause the display unit to malfunction internally, and make it think it had received warning signals, or did those sensors actually trigger (indicating they are actually wired to the display after all).
I think I may have to find one of those inputs and deliberately trigger them, to see if the display reacts at all.
If the wiring isn't matching up correctly I might just have to leave it, sounds like a hell of a lot of work to wire this from scratch, if indeed the different engines have different sensor wiring where the dot matrix is concerned.

Anyone would think I didn't have a dozen other XM problems to look at....

Cheers

Ciarán

[xmexclusive]

Hi Ciaran

Lets start with a couple of odd questions. What size is the RIGHT HAND display perspex cut out (62mmx15mm or 82mmx20mm) and does the washer stalk have a rigid end or one that pushes in like the horn button on the other stalk?
The TD dash should have the small cut out and the fixed end stalk but my guess is you will find that the Petrol bits were left insitu.

Regards

XMexc

[Ciaran]

Hiya XMexc,

Once again you are quite right. I don't have the display measurements to hand, but I can tell you that its the larger one with the push button stalk and fuel computer (which works aside from MPG of course!). I do have the displays from a diesel S1 car and know that my S2 right-hand one is certainly larger.

So yes, I think we can surmise the petrol wiring has been left in place. That answers a lot really.... I did think the sensors for things like engine temp, hydraulic pressure etc were generic, but there you have it, seemingly not!

[Zaphod]

There is another posibilty,, your S1 display mearly likes to talk, I know the one on mine occasioanlly suffers the odd bout of verbal dioreara when it gets bored I think!

Stewart