XM tyres

[Peter.N.]

A 2.1 td manual is the only one I would be thrilled about the prospect of.

Peter

[xmexclusive]

Hi Mike

Do not know too much about BX ABS.
A quick look in the early ABS reference book shows it as being specified by Citroen a couple of years earlier than the first XM system.
The CX ABS was specified at the same time as the BX one and ZX a couple of years after the XM.

So I have found some production dates:
BX - 1987 to 1992 - Teves ABS
CX - 1987 to 1990 - Bosch ABS
XM - 1989 to 1995 - Bendix ABS - Rings 48T (check shape of teeth on very early cars).
ZX - 1991 to 1994 - Bosch 2E ABS
Xantia - 1993 to 1996 - Teves Mk4 ABS
ZX - 1995 to 1998 - Bosch 5.0 ABS
XM - 1996 to 1998 - Teves Mk4 ABS - Rings 48T
Saxo - 1996 to 1997 - Teves Mk4-GI ABS - Rings 48T
Xsara - 1997 to ? - Bosch 5.3 ABS
XM - 1999 to 2000 - Teves Mk20 ABS - Rings 48T

It seems that Citroen kept the options open and costs down by using the all the available suppliers.
Your prompting with this topic has got me to pull that list into one place.
I would love to add ABS ring teeth numbers and sensor position to that list.
There are some positives from my ABS research so far.
We are now certain that Teves XM sensors can be modified to work Bendix XM ABS.
I now have on order Saxo Teves sensors to compare them to XM Teves sensors.
Relative availability and prices are the key item here.
New XM Bendix sensors are rare as NOS and £200 a time.
New XM Teves sensors are still widely available at £45 a time.
New Saxo Teves sensors are also widely available at £15 a time.
It seems the pricing is not technical complexity just volume made.

When the Saxo sensors turn up I need to check them out dimensionally, electrically then practically if they are viable.

I have now also extended the ABS league table above to the other PSA vehicles of a similar age with ABS.
The info is:
Pug 505TD - 1983 to 1990 - Teves ABS
Pug 505 V6 - 1986 to 1989 - Teves ABS
Pug 405 - 1988 to 1992 - Bendix Addonix ABS
Pug 405 Mi-16 - 1988 -1990 - Bendix Integrated ABS
Pug 205 - 1990 to 1992 - Bendix Addonix ABS
Pug 605 - 1990 to 1992 - Bendix Integrated 3rd generation ABS - Rings 29T
Pug 309 - 1991 to 1992 - Bendix Addonix ABS
Pug 106 - 1991 to 1995 - Bendix Addonix ABS
Pug 306 - 1993 to 1994 - Bendix Mecatronic 1 ABS
Pug 605 - 1993 to 1995 - Bosch 2SE ABS - Rings 29T
Pug 306 - 1995 to 1996 - Bosch 5.0 ABS
Pug 406 - 1995 to 1996 - Bosch 5.0 ABS
Pug 605 - 1996 to 1997 - Bosch 5.0 ABS - Rings 29T
Pug 106 - 1996 to 1997 - Teves Mk4-Gi ABS
Pug 306 - 1997 to ? - Bosch 5.3 ABS

Note the Pug 605 started off with Bendix ABS but using 29 tooth rings.
I can now get hold of wiring and test diagrams for all the ABS that I have listed above.
If I find copies of the Pug and Cit workshop manual I will add a note to the entry.

John

[citsncycles]

Don't know much about the BX ABS myself, except that sensors are like rocking horse poo and the last NOS one I saw for sale went for £140! Usually the issue with the BX system is the wire out the back of the sensor failing, which can often be repaired, but I believe that trying to remove the rear ones at least usually results in them being destroyed in the process. A couple of years back somene did look into it and thought that it may have been possible to use Escort sensors from the same period if the connectors were changed, but I don't know if it's been tried by anyone.

At present the ABS on the XM only seems to stop working when the voltage supply is lower than ideal - if it doesn't work on start up I generally find pulling over and restarting after 5 minutes generally sorts it out.

[Dieselman]

That's true. My TZD estate would throw the ABS light on at an indicated 80mph. No other time. I thought it was some sort of speed nanny!

I guess I may have to say goodbye to those lovely tyres then. Hoping someone will buy the Rover soon so I can finally grab a slice of XM ownership. Can't imagine why I'm thrilled at the prospect of a Mandarin 2.1TD manual...

Is this the high mileage one at Derby, if so, buy it, it was a very presentable car.

[dollywobbler]

Nope. This is another one that is on this forum. Won't say more until actual folding stuff has changed hands though!

[White Exec]

Mike said: "At present the ABS on the XM only seems to stop working when the voltage supply is lower than ideal - if it doesn't work on start up I generally find pulling over and restarting after 5 minutes generally sorts it out."

On a diesel, I wonder if it's unfortunate that the ABS system is running its start-up check just at the exact moment that the glow-plugs are pulling the battery voltage down? One way to find out, Mike: temporarily disconnect the GP feed, and see if anything changes (probably no need to actually start the engine...). Just a thought.

[citsncycles]

Ah, that's worth a try. I dunno if this is normal, but it actually goes through the check twice, once when the glowplugs are heating, then again once the starter has been operated. Sometimes, it'll fault the first time then be alright the 2nd time.

[xmexclusive]

The XM Bendix ABS has 3 separate power supplies.
The ignition switch starter position is wired to drop one of those supplies while the starter operates.
It is that dropping of one power feed that resets the ABS ECU and makes it run through its light blinking start up routine.
The ABS ECU minimum operating voltage is below the battery minimum of 10.4 volts.
You can see this feature by gently nudging the ignition switch towards the starter engage position with the engine running.
Be very careful not to engage the starter.
The ABS light will then go through its blink start up routine.

John

[citsncycles]

Will have to try that sometime, thanks - may avoid stopping to restart again.

[White Exec]

"...but it actually goes through the check twice, once when the glowplugs are heating, then again once the starter has been operated."
My S2 2.5 does exactly the same, and John's info explains why - and confirms that the system should tolerate the preheat cycle.

I've had intermittent non-extinguishing of the ABS warning light on start-up (or IGN on), and display of 'ABS out-of-use', for a few weeks now. Like yours, sometimes switching off and leaving for a short while seems to clear the fault. Last few days it hasn't.

Tracked fault down to ABS Relay [844] ((((check whether this is relevant for your S1)))), a 6-pin Citroen special near the battery box/behind-below the headlight. Job of this is to keep the dash ABS warning light lit if the electrical supply to the ABS fails, and to extinguish it if the supply is OK. Mine had not only greeny base contacts, but had a touch of rust inside! All now cleaned up and ok. Wonderful location for a bundle of relays!