Citrojim's Pixo, Saxo and Cycling Tales

[CitroJim]

Sorry for the long absence Hopefully I'm back and able to look and catch up slowly on what has been happening here. Until now I've just not had the mental facility to concentrate on the forums. I open them, start reading and just loose the will to go on. So I close down and go and do something else that takes a lot less mental effort...

I've not had the mental ability to drive far either and hence why the Activa has been put away again Clutch and gears were just far too much to cope with

There was no way I could even attempt such a trip such as going to Wetherby and back..

Things are still not right so please bear with me a little.

Anyway, yesterday I did manage something significant. I finally got the ELIT talking to the gearbox ECU on my XM I made up a custom lead and indeed as I suspected I established a dialogue by speaking S2 Xantia to it. The difference that the S1 Xantia and XM speaks to the ECU using only the K diagnostic line whereas the S2 Xantia uses both the K and L lines..

So the car definitely has an S2 Xantia ECU fitted.

The fault turned out to be a torque reduction fault whereby the ECU cannot signal to the Engine ECU to retard timing (and thus reduce torque) when making gear changes. The fault cleared and so far has not reappeared..

Looking at the circuits for both the S1 and S2 Xantia I see that on the S2 both K and L diagnostic lines from the engine and gearbox ECUs are linked together whereas in the S1 they're not, only the K line being linked.

I'm wondering if the ECUs talk to each other over the K and L lines?

The research goes on but I believe the Engine ECU and gearbox ECU may be incompatible with each other. Not to worry though as it doesn’t seem to cause much issue with driving but may explain whey the car feels very lively...

Now off to try and catch up on what's been happening. That's if the old brain will let me

[Hell Razor5543]

Welcome back Jim.

[CitroJim]

weather related perhaps? That's been up and down recently, barometric pressure does strange things.

I'm wondering that Mike, I seem to be much better in the winter

Welcome back Jim.

Thanks James, it's good to be back

[lexi]

Is the fatigue affecting the mental capacity Jim? You are maybe using it on other things ( work) and have none left when you come to a job you would like to complete.

Combined with your illness Jim it does not take long at our age to lose the ability to do what we did only a few years previous. I know that sounds silly but when I think what I was getting through just 5 yrs ago...can't do it now and it ain't justthe medical reasons. I bet if you look around you the guys your age ain't doing as much as you?

Here is wishing your health mate

[CitroJim]

Is the fatigue affecting the mental capacity Jim? You are maybe using it on other things ( work) and have none left when you come to a job you would like to complete.

Very much so Lexi, it's a cardinal part of ME and it's known colloquially as 'Brain Fog' which is a pretty good description of it really. It's like your head is full of fluff and cotton wool. Clear logical thought and concentration on mental tasks is all but impossible. As I say, you start to try to read and you loose the will to go on.

Yes, work depletes a lot of my mental energy, that's for sure. I'm good today as I'm enjoying my day off - my middle weekend in my part-time work scheme! It affects me at work too and some days I have to leave early as I just can't carry on...

Today I'm just physically knackered.. The brain is quite good. Some days I have a rare convergence whereby my brain and body are good at the same time Not as often as I'd like though and such days just can't be predicted or anticipated. Normally one faculty or the other is down in the grass and some days both are

I know what you mean about age Lexi but I look at those around me the same and older and they can do far and away more than I can and live far unhealthier lives. I don't smoke, I don't drink, I eat a very healthy diet, I exercise as far as I can, I don't chase loose women and yet I get tired just listening to what some of my friends have been up to recently

Still, I do still grab life by the balls when I can. I refuse to totally abandon my life to this and let it get the better of me. Occasionally I really suffer because of that attitude but bugger it - life must be enjoyed...

[lexi]

Ah! righto Jim. I am kind of shocked to hear of this.

'Tis a true saying right enough...........you can't choose your family, or your illnesses...

[CitroJim]

'Tis a true saying right enough...........you can't choose your family, or your illnesses...

Indeed and sh*t happens You just live with it and get on with it. Big issue is that I look very well and healthy (result of necessarily having to live healthily and carefully) so people don't understand just how things are. So many associate illness with looking rough and an illness where you look in the pink causes awful confusion... And it doesn’t help it's a fluctuating condition...

Still, it's not fatal or terminal - in fact just the opposite. All the necessary healthy living is likely to extend life so every cloud has a silver lining...

In fact there's a very dark joke in there... The good news is that ME is not terminal. The bad news is that ME is not terminal...

Off out in a bit to see if my gearbox has remained fault-free...

[Hell Razor5543]

That joke reminded me of an incident whilst travelling back from seeing family in Germany. I have been blessed with a strong stomach (well, it has to put up with my cooking!). The weather in the Channel was somewhat rough (roller coaster, more like), and I was one of the few not affected by this. I nipped off to use the toilet, and saw somebody throwing up into one. To comfort him I told him that nobody dies of travel sickness, to which he replied "Oh God, don't say that! It's only the thought that I might die that is keeping me going!"

[Northern_Mike]

weather related perhaps? That's been up and down recently, barometric pressure does strange things.

I'm wondering that Mike, I seem to be much better in the winter

This just shows how it affects different people in different ways. I find the cold weather, or at least getting cold, absolutely ruins me for a couple of days. Even walking down the mile or so into the village will do me in. What's worse is that I feel ok before I set off, and forget..

I actually went to bed at a normal time, as I wasn't working on Monday night. I was utterly, completely drained. Head fog, cracking headache and pain. I fully intended getting up at about 10am to have a day with Sam and Adriana for a change. I finally woke up at 2:15pm. Fell asleep in the chair again at 9pm, got woken up by the cat at 10:30 when I went to bed, and slept until 8am this morning. I feel a little better, but still foggy.

I washed and polished the MX5 again on Monday afternoon.... I felt fine before that. Crazy really

[Northern_Mike]

Is the fatigue affecting the mental capacity Jim? You are maybe using it on other things ( work) and have none left when you come to a job you would like to complete.

Combined with your illness Jim it does not take long at our age to lose the ability to do what we did only a few years previous. I know that sounds silly but when I think what I was getting through just 5 yrs ago...can't do it now and it ain't justthe medical reasons. I bet if you look around you the guys your age ain't doing as much as you?

Here is wishing your health mate

I don't think it's an age thing really. As Jim says, and I've seen it with my own eyes, he looks a perfectly healthy specimen when you see him. I'm told I do as well. I have not been officially diagnosed with ME, the doctor and therapist call what I have "post-viral fatigue", which seems to be essentially the same thing. I don't seem to suffer from it as badly as Jim does, but then again I'm not inside his head or body, and can't compare how he feels to how I feel. It's like I've got a really, really bad hangover, but without the rough stomach, feeling sick, or pounding head (most of the time). Just a complete and utter lack of energy and being unable to think at all. It's not like I "can't be bothered" to do stuff, I really want to, but I simply can't. I have to take medication for the pain it gives me, which helps, but it makes me a bit (more) dopey occasionally, and gives me the munchies!

Then on other days, I feel bright as a button and go to the gym for 90 mins, or go swimming/cycling for a couple of hours and feel fine..

[Northern_Mike]

'Tis a true saying right enough...........you can't choose your family, or your illnesses...

Still, it's not fatal or terminal - in fact just the opposite. All the necessary healthy living is likely to extend life so every cloud has a silver lining...

Wouldn't you just like a really nice big piece of cake sometimes Jim, or a ciggie, or a nice pint?

I know I would! It's been over 12 months since I had a drink, I think I had two cigs that night, and it was years before that..

[CitroJim]

James, loved the seasick tale. Been there, done that on a landing craft off the coast of Cyprus. You really do want to die

Wouldn't you just like a really nice big piece of cake sometimes Jim, or a ciggie, or a nice pint?

The ciggies and booze hold no interest Mike and the cake is no problem at all. Whilst shop-bought stuff is not good for me I have a solution. I bake my own Once a week I knock up a CitroJim special rich fruit cake from scratch and enjoy it through the week.. Sorted...

Speaking of sorted, something which isn't is my XM gearbox ECU

Yesterday I noted that as far as I could see the faults were still clear so I tried popping the ELIT onto it to see with the engine running. Upshot is that I can communicate with the ECU and read and do everything on it now except read faults This is bizarre and I'm wondering if running diagnostic leads across the top of the running engine has induced enough interference into the lines to zap the ECU? It's odd as the ECU is still working perfectly as far as controlling the gearbox goes although I can see from the display it has a stored fault again and everything works diagnostic-wise except being able to read faults... Only an XM could do this

That'll keep me busy over the weekend. I have the whole of next week off so lots of time for car play.

I think, on reflection, it was yesterday, one of those days when the ABS light came back on in the Xantia V6 so that sensor I thought was OK wasn't in the end and my neighbour's boiler and electric shower packed in simultaneously. Sadly, nothing I could do as the boiler had a serious water leak from something internal to it and the shower had died of old age.

The good bits of yesterday was the vet only charging me a tenner for Fluffball's annual demat and an excellent meal Siany and I cooked in the evening; an absolutely epic thai green curry Actually it wasn't cool - the additional chilli and ginger saw to that

[Mandrake]

Sorry for the long absence Hopefully I'm back and able to look and catch up slowly on what has been happening here. Until now I've just not had the mental facility to concentrate on the forums. I open them, start reading and just loose the will to go on. So I close down and go and do something else that takes a lot less mental effort...

I've not had the mental ability to drive far either and hence why the Activa has been put away again Clutch and gears were just far too much to cope with

There was no way I could even attempt such a trip such as going to Wetherby and back..

Things are still not right so please bear with me a little.

Sorry to hear you haven't been well again recently Jim, the forum is always a lot quieter and a bit more boring without you around.

Anyway, yesterday I did manage something significant. I finally got the ELIT talking to the gearbox ECU on my XM I made up a custom lead and indeed as I suspected I established a dialogue by speaking S2 Xantia to it. The difference that the S1 Xantia and XM speaks to the ECU using only the K diagnostic line whereas the S2 Xantia uses both the K and L lines..

So the car definitely has an S2 Xantia ECU fitted.

The fault turned out to be a torque reduction fault whereby the ECU cannot signal to the Engine ECU to retard timing (and thus reduce torque) when making gear changes. The fault cleared and so far has not reappeared..

That is odd Jim, because as far as I know the torque reduction control line is a one way signal that doesn't accept any feedback in the reverse direction ? It encodes both gear shift and torque reduction requests into one signal which is sort of digital but includes analogue ramps...

Looking at the circuits for both the S1 and S2 Xantia I see that on the S2 both K and L diagnostic lines from the engine and gearbox ECUs are linked together whereas in the S1 they're not, only the K line being linked.

I'm wondering if the ECUs talk to each other over the K and L lines?

Nothing that I've read suggests that any of the ECU's on a Xantia talk to each other over the K and L diagnostic lines Jim. It's not like a multiplexed CAN bus on later cars where the bus is also used for inter-ECU communication, its purely a shared serial diagnostic bus where the interrogated ECU's take their turn responding to the Lexia but don't talk to each other. As far as I know all inter ECU communication (certainly between the engine and gearbox) is done on discrete dedicated lines such as the torque control line.

One reason why is that the data rate on the K and L lines is just too slow for rapid updating of data! The engine RPM signal from the engine to gearbox from memory is updated every 10ms for example and is sent as a PWM waveform rather than binary data. Come to think of it, the very slow half duplex data rate of the K and L lines is probably why its not possible to graph multiple real time sensor data on a Xantia using a Lexia, yet the Lexia can do it on a C5. Just not enough bandwidth.

[Mandrake]

Speaking of sorted, something which isn't is my XM gearbox ECU

Yesterday I noted that as far as I could see the faults were still clear so I tried popping the ELIT onto it to see with the engine running. Upshot is that I can communicate with the ECU and read and do everything on it now except read faults This is bizarre and I'm wondering if running diagnostic leads across the top of the running engine has induced enough interference into the lines to zap the ECU? It's odd as the ECU is still working perfectly as far as controlling the gearbox goes although I can see from the display it has a stored fault again and everything works diagnostic-wise except being able to read faults... Only an XM could do this

If you've just run loose wires across the top of the engine bay then I'd say yes, ignition interference pick up may be confusing the ECU. I had a similar issue while diagnosing the ignition system on my V6 - I had the laptop sitting above the battery with the USB cable running in through the passenger window to the Lexia box, I was using the Lexia to manually operate the ignition coils to test the coil pack. I had large spark gaps set up above the top of the engine in the coil pack area to see how far I could get the spark to jump from the coil, with a large gap (20mm or about 60,000 volts!) my test would frequently stop working and the Lexia could no longer talk to the engine ECU... it would just sort of freeze and say that the ECU wasn't responding even though the ECU was continuing to fire the spark once per second until the completion of the test! (I had just lost control of the ECU with the Lexia, and wasn't able to stop the test or perform another one)

Whenever this happened I had to turn the key off for a few seconds and back on again to get them to talk to each other again. It didn't happen with a 10mm (30,000v) spark, so its clearly RFI related. For the gearbox ECU you might find you have to lift the battery off for 30 seconds and I think you'll find they talk properly again.... if so you might need to run your wiring somewhere more RFI friendly.

[CitroJim]

Simon, thanks. An excellent set of thoughts there

Looking again I believe you're right on the torque reduction side of things... In the S2 the K and L lines from the Engine and Gearbox ECUs are tied together because they can be as the protocol allows that. the L line is used to 'wake up' the ECU you wish to speak to on the K-Line..

Interesting stuff..

I shall try some tidier wiring g over the weekend and see how it goes! The temporary stuff was a real rat’s nest just to test and I have a 16 pin OBD socket on order so I can do it properly..