CitroJim's AX, C3 Picasso, Cycling and Running Tales

[CitroJim]

I've never dared count Ben but I reckon about 12 to 15 mugs a day All decaffeinated and a mix of the standard PG Tips stuff and Twinings Earl Grey - the latter mostly in the evenings...

Could do with one of those urns that always provide boiling water, but I think I would be at risk of doubling my coffee/tea intake if I did.

We have those at work, the old Zip Hydroboil, and it's just too easy. I've got an almost constant cup of tea on the go at work. PG Tips must love me

[Hell Razor5543]

Waitrose are doing Twinings tea at £3 per 100 bags but NOT (GRR!! ) the decaf variants, otherwise I would have bought in a couple of boxes for you, Jim.

[myglaren]

Get ready to pay more for your tea.

The Independent.

[CitroJim]

Get ready to pay more for your tea.

For me that is terrible news Steve.

Still, with climate change perhaps we'll soon be able to grow our own, perhaps in the Welsh hills and then we'll have our own independent source... Will bring a whole new meaning to English Breakfast

Or should it then be called Welsh Breakfast?

Or will it all end up just being a dog's breakfast?

[Xaccers]

Get ready to pay more for your tea.

For me that is terrible news Steve.

Still, with climate change perhaps we'll soon be able to grow our own, perhaps in the Welsh hills and then we'll have our own independent source... Will bring a whole new meaning to English Breakfast

Or should it then be called Welsh Breakfast?

Or will it all end up just being a dog's breakfast?

How about Tregothnan's Cornish tea?

http://www.tregothnanshop.co.uk/search.asp?types=**TEA" onclick="window.open(this.href);return false;

[CitroJim]

http://www.tregothnanshop.co.uk/search.asp?types=**TEA" onclick="window.open(this.href);return false;

Have you see the cost of it It would bankrupt me

And no decaffeinated

[CitroJim]

A good and successful day today. feeling a bit perkier so I've been gently playing XM electricals. I've fixed my aircon I now have a blower that works properly last time I looked I saw an unvarying +5V at the blower regulator control line and assumed the climate ECU was dead. Swaps of two good ones later I realised it wasn't.. Today I paid a bit more attention to the blower regulator and noted it was an after-market job and it looked brand new. I had a spare Xantia one in stock but that didn't work either but caused the fan not to run at all! After a set of new transistors were fitted to the Xantia one all was happy and the blower works, temperatures regulate and the aircon blows cold. Excellent!

I was curious to see wht the new after-market one wouldn't work. All seemed OK and then I noted the markings on the transistors was a bit indistinct but it looked like they were MJ11016 rather than the correct MJ11015. odd.

I looked up the data on the MJ11016 and found they are the complementary NPN to the PNP MJ11015 so no wonder they wouldn't work. Gawd knows where this module came from but it was never going to work with the wrong trannies in it, that's for sure and it was how it was made as the transistors are riveted in...

I then turned my attention to the non-operational cruise control. All tests tell me the ECU is dead as the vacuum pump and dump valves work a treat, all signals and voltages are correct, including the speed signal which I tested by rigging up a battery-powered oscilloscope on the passenger seat, some very temporary wiring and going for a very short drive.

Easy I thought. I have a spare S2 Xantia cruise ECU in stock but they're just different enough not to want to play

So, I need a new ECU. Anyone got one please? The Hella part number is 5GA 004 397-17. I know a Xantia S1 one is the same as well but not the Xantia S2. How bizarre...

A good day but a bit knackered now. Next I'll see why I can't speak diagnostics to the gearbox ECU...

[spider]

As you've said using NPN vs PNP will not work, I'd guess they had a bad batch at the factory / parts assembly and they'd just assemble them anyway ? , would only take a few to fall into the wrong 'tray' I suppose.

What's inside the Cruise ECU Jim, have you had a peek to see if its anything likely to be 'home fixable' ?

[CitroJim]

What's inside the Cruise ECU Jim, have you had a peek to see if its anything likely to be 'home fixable' ?

I have Andy and there's a bit of electronics in there..

I found a thread on an Audi forum and they suggest that dry joints are a problem. I shall see if that works for mine...

The thread linked above has a picture of the inside of the ECU but to get to it you have to scroll past nasty pictures of an Audi TT and some other Audi thing I confess I don't recognise...

All I know is that some older Audis used the same cruise control as the XM Gives an Audi a bit of much needed class I suppose...

[DHallworth]

Interestingly Jim, I bought the circuit board for the blower from eBay. The old transistors were dead and as they've already been changed twice I decided to buy the board at £16 instead of the transistors at £14 odd from RS Components.

I bought this one: http://www.ebay.co.uk/itm/Heater-Blower ... 7675.l2557

I fitted it and the fan didn't work at all. After contacting the seller they said that they've had the same problem with it from other customers.

After a quick check I've noticed that it's got MJ11016 transistors on it too.

David.

[CitroJim]

That's the same one David!

Isn't it interesting that in the e-bay picture the transistor markings are scrubbed off

I feel for a lot who may have bought them in good faith as they might have done as I did and wasted a lot of time chasing red herrings...

Still, as was said on Club-XM it was worth £16 to get a nice new shiny board and heatsink! The module I resurrected was a really scruffy old thing that was very corroded. Took longer to clean it up than it did to replace the transistors!

[CitroJim]

Sadly I discovered today that my XM cruise issues were not down to dry joints

It was never going to be that easy

Not one to give up on these things and with a need to know what had died I looked in vain for a circuit diagram of the ECU. Couldn't find one so I drew the important bits - those that drive the vacuum pump - myself..

It turns out it has an 8-bit microprocessor to do all the magic bits but of more interest was the business end of it as I suspected that was most likely where any problems might be. I discovered in my drawing that it has a safety relay, much as in an ABS system, that supplies 12V to the vacuum pump, dump and vacuum regulator electrovalves of which the latter two, the pump and vacuum regulator, are controlled by a hefty power transistor and a much smaller pair of transistors respectively that switch on to earth the respective components and make them run. All pretty standard open-collector switching stuff really.

In testing found a short-circuit zener diode which sits across the vacuum pump motor effectively and acts as a back-emf suppressor and also found the two small transistors that drive the vacuum regulator both very faulty. The hefty transistor which controls the vacuum pump seems to be OK when tested on an AVO.

That appears the sum total of dead bits and I wonder how it happened as normally cruise ECUs are like granite - indestructible...

I can only think that someone may once have tried it on an S2 Xantia which uses a slightly different ECU in that the connections to the vacuum pump and regulator are reversed. This would mean the small transistors would try to drive the high current vacuum pump to their own detriment whereas the vacuum regulator being driven by the pump control circuit would have generated a hefty back-emf and blown up the diode...

I've ordered the bits and will try a repair. I'm not holding too much hope though but it'll be interesting to see if I can make it work again...

I've quite enjoyed my dabble into electronics today. It's been a long time since I've gone that deep into such things...

In other news I reprogrammed my XM immobiliser keypad so that it automatically unlocks when the car is unlocked with the plip. Bizarrely this functionality is not available in the S1 Xantia keypad it seems...

Now I must not forget the keypad code as it's needed if the car is left unlocked for a period...

[hattershaun]

Jim, you can always lock then unlock the car with the remote control, if you forget the code and the auto function has timed out. I think you get 60 seconds to start the engine after unlocking with the remote control.

[CitroJim]

Thanks Shaun Didn't think of that. I can be so stupid sometimes

I've written the code down so I won't forget it. That is as long as I can remember where I wrote it!

[myglaren]

Put a post-it note next to the alarm pad Jim