V6 Xantia......... the beginning of another adventure

[DickieG]

Right, just finished breakfast - off we go to have another go at fixing...

Oi what time do you call this Jim you having a lazy day? I'd have thought you would have been at for at least three hours by 8am

[Trainman]

Says he's been up since 4am....... not sure about that, but about to test the brownies, so if he suddenly acquires another Xantia...... it was mine *gulp*

[daviemck2006]

Then if your v6 goes to Sir Jim then you could get his activa to lpg :oops::lol::mrgreen:

[Trainman]

Then if your v6 goes to Sir Jim then you could get his activa to lpg :oops::lol::mrgreen:

If these 'brownies' kick in I won't be fit for anything......

[KP]

Ha ha! Are they chilli brownies?

[Trainman]

Ha ha! Are they chilli brownies?

No, Chilli for tea........

[myglaren]

Ha ha! Are they chilli brownies?

or 'hash' brownies

[KP]

Ooo lucky you

[CitroJim]

Yep, been up since 4. Washing done, two applie crumbles baked and the aforementioned brownies whih I'm sorry to disappoint you, are just normal ones with no 'additions' at all...

Just now trying to download a new software image to the spare ECU for Steve. It's taking ages...

[KP]

Ooo I didn't realise there were firmware updates for ecu's on our xantias Jim! Where and how do you get them?

[Mandrake]

Yep, been up since 4. Washing done, two applie crumbles baked and the aforementioned brownies whih I'm sorry to disappoint you, are just normal ones with no 'additions' at all...

Just now trying to download a new software image to the spare ECU for Steve. It's taking ages...

Noooooooooo.......!

You'll add the depolution "feature" which holds 1st to 3300rpm for two minutes when cold...

I deliberately did NOT update the gearbox ECU firmware on my new V6 after making that mistake on the first one...

(I did update the engine ECU firmware though )

[CitroJim]

I know but sadly I had no choice. I was using the ELIT and the menu took me somewherte I really didn't want to go

Before I knew what was happening a download had commenced...

I have reinitiliased an S2 with the ELIT but the S1 menus look different...

Hopefully no damage done...

[Mandrake]

Oh well, if that fails, you have a Lexia as well ? Fortunately there seems to be a ROM based boot loader in the gearbox ECU - as it seems to be possible to recover from a failed upload. How do I know ?

Yes, I had a failed upload on my first attempt on the old car which left it in a state of hydraulic emergency mode and flashing sport/snow lights even after a battery off reset - I thought it was toast but it responded to a second upload attempt after the battery had been removed and all was well after that.

On the newer firmware if the gearbox oil temp is below a certain temperature then it always does the depolution thing for the first two minutes - every cold start in the morning without fail.

On the older firmware in my new V6 it doesn't do the depolution thing on the first cold start of the morning - it changes up at normal rpm immediately, however sometimes later in the day a subsequent warmer start will exhibit behaviour similar to the depolution mode where it holds 1st to higher rpm for a while...

I think the cause of that can be explained though - from what I remember from the manual the currently active adaptive program (SK1-6 etc) is memorised at switch off and if the gearbox oil is warm (above 30 degrees ?) it resumes immediately in the previously memorised SK mode. So if you were driving in a very sporty fashion shortly before you switched off, when you start up next it resumes in that sporty mode where gears are held higher.

However if the oil temperature is low during startup (as on the first start on a cold morning) it always begins in SK2...

Anyway, I'm leaving my ECU firmware alone and I kinda wish I hadn't done the auto adaptive reset either...

[Trainman]

Jim discovered that the engine speed sensor wasn't getting a constant signal, and when it did get a signal it was fluctuating so much it was almost unreadable. He is now studying his electrical wiring bible......

More later

[Mandrake]

Interesting.

Jim - are you measuring it at the back of the ECU connector ? I definitely remember getting an inconsistent, much lower than expected signal from the crank sensor on my old V6 too when I was first trying to measure it, but I'm pretty sure it turned out to be a measurement error.

I'm sure you know this - but it's a floating differential signal on pins 48 and 49 with pin 19 as the shield... From memory I think the error I made was to try to measure pin 48 or 49 relative to earth assuming the differential signal was balanced around earth as I was also trying to measure another signal on a second channel. (and thus share the earth reference for the scope)

But it seems the crank signal may be transformer coupled inside the ECU (with no earthed centre tap) and therefore truly floating with no earth reference, thus it can't be measured with respect to earth.

Measured with respect to earth I was seeing only a few hundred millivolts and it kept changing all over the place. With the scope between pin 48 and 49 I was seeing a strong consistent signal. From memory it was about 2v p-p at idle rising to nearly 10v p-p at about 2500 rpm... my figures could be a bit out, but it was many volts worth of signal.

It would be nice if you find a genuine fault with that signal though.