Anthracite XM 2.0 SEi Turbo Manual

[xmexclusive]

Now is the time to get spare switches.
Citroen stock of new most likely will go NFP soon.
Secondhand will get hard to find as more cars get crushed.
Better to overhaul a spare SH switch than the one on your car.

John

[Aerodynamica]

I rebuilt the switch today - certainly did have some metal swarf (very fine too) in among the small amount of grease. I think It'll work ok now

[Aerodynamica]

Well, a few weeks after the rebuild of the switch I have not seen the problem recur. If anyone gets this problem, it's true you can clean the contacts to good effect.

Car cut out three times this morning due (i think ) to the idle control unit. It always restarts and runs well - no problems tonight on the way home. I need a replacement idle control stepper motor for the Bosch multi point turbo system if anyone has one for sale.

Just thinking about the problem I have with the vehicle speed sensor for the hyperative and the trip computer. I was thinkint the fault might be in the fuel computer and didn't know how to eliminate it in my ongoing investigation but just realised that the trip computer CAN'T be part of the issue as it must only receive an input, not supply one to the hydractive. Simply that some XMs don't ave the trip computer! and they do have Hydractive with a speed sensor! Why didn't i think of that already!

Anyway, the odd thing about the fuel computer is that although it shows no average speed reading, displays MPG as 99.9 mpg, shows the average mpg as ---, it does, however, show the miles left range as a fairly accurate figure that changes as you go. Does this have a single, seperate feed? (sorry , I realise nobody knows anything about the fuel computer inputs but I have to ask for any info!) so it makes me think the speed sensor truly is the stand- alone fault.

I'm so keen on solving this speed sensor issue.

But MOT due in less than 2 weeks. I've replaced 3 parts of the exhaust including a new catalyst and now the final part (rear crossbox) has fallen apart.. trouble is the item that comes up from the various suppliers is different from the actual one on the car!! The one on the car at present is exactly the same as that of the NON turbo 2l XM. So I've ordered the visually identical part from the non turbo. The item shown for the TCT XM differs in the connection to the centre box pipe.

Anyway, wish me luck for the MOT next week!

[mds141]

Good luck with the MoT Graeme.

[xmexclusive]

I can confirm that the RH display gets separate signals for each function.
Cars without the extended display are like that because there is no engine ECU to calculate performance.
Fuel in tank is a direct feed off the tank sensor.

Citroen used 4 different speed sensors during the life of the XM.
Initially the first two were used on setup's like yours.
A mechanical drive box fitted to the gearbox and a mid cable mechanical to electrical converter.
The next stage was a Dual mechanical and electrical drive box fitted to the gearbox.
The final stage was just an electrical box fitted to the gearbox on Mk2 XM's.
Now the gearbox fixing and footprint is the same for all 3 boxes that fitted to the gearbox.
In fact many early Mk2's got the late Mk1 dual box with a rubber bung in the mechanical drive hole.
Might be worth you finding one of those dual boxes to try, they may even still be available.
It gets better.
On late Mk 1's and all Mk 2's Citroen did not make a new loom with continuous wiring.
No crosses or funny wiring. 4 wires pin to pin between the plugs.
They all have a short link cable and plugs to extend back to the gearbox.
Cable joint is found under the back of the LHM tank.
Just need a check on the wiring and plug to that mid cable connector.
Be worth checking out I think.

The exhaust variations is the result of Citroen using factory made exhausts without joints.
I have seen a guide to tell dealers where to cut exhausts to replace sections.
This let the aftermarket suppliers do their own thing so there is a fair bit of variation and confusion about what will fit.

John

[Aerodynamica]

Cheers guys.

That's really useful info John but mine is a series one proper so with hydractive 1 and maybe doesn't have the right wiring for this?

I'm wondering if I could send the sensor to a member to run in their XM to see if it is the sensor itself.

Any volunteers?! Hahaha

Only question about the trip computer now is how does it know the range left in the tank if it's not getting the speed info?

[White Exec]

Similarly puzzled. Would have thought it would have used mpg info coupled with fuel remaining (i.e. voltage from float) to compute the Range figure.

I know from experience that when you're running out of fuel on service-stationless German autobahns in the small hours, if you go feather-footed, you can actually get the Range to increase while you're speeding along into the night.

[Aerodynamica]

Haha these XMs run on air!

[xmexclusive]

On a 2.5 the computation of miles remaining is done every 20 seconds by the ECU.
The ECU is instructing the fuel volume to be injected.
From that and fuel in tank signal it can easily work out how much further it can run at current usage.
A car where the ECU is just monitoring the engine can still do the same calculation.
Just a bit more crudely based on fuel remaining and average usage.
An XM with no ECU has no processor to do the calculation so gets the simple display.
As far as I am aware there is no link between speedo drive output and XM ECU's.

John

[White Exec]

Makes sense, John.