Abs Sensors - CITROEN XM Internet Reference

93 ABS sensors

The brakes
93 ABS sensors
I own a xm2ltr sei 1990 and my abs error light keeps coming on when I come to a stop say at a
crossroad, then goes out when I move off again. Local garage says it it the left rear sensor, so I change
it at #74 plus vat. Same problem still, then I Measure out all sensors the left rear measures 2500 ohms,
all other 3 1500 ohms.
An imbalance? garage says I have to change right rear to balance out rear axle.
No thank you,, what about supplying the correct one I ask, dont make them anymore is the reply, so I'm
off to the scrap yard. any one had the same problem? all wiring and plugs cleaned and checked. I
thought it maybe another earth problem.
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I have had many ABS problems on my XMs. Last XM was a real p.i.t.a. I had to change the left front
sensor twice within 2 years and then the problem was gone, although all sensors give different
measurement values. The cables on which the sensors are attached are not reliable. They are easily
damaged inside because of steering etc.
We have had these discussions before, but my opinion is that it's the sensor cables that are the problem.
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ABS- light comes on, and stays on, when first starting. Can be 'cancelled' by restarting engine (ie
turning ignition off, and then on again) after travelling a short distance (from 1m to 1km!) Diagnostic
tests indicate a problem with the left rear sensor. Solution, do nothing, alledgedy there is a batch of 'over
sensitive' (??!!) ABS units which have been installed on some series 2 XMs.
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Hi fellow readers, well I tried putting a 2.5 kohm res in parallel with the left rear sensor so that at
standstill they all read the same value ie approx 1.5 k ohms. It didnt work., because the sensor is a
magnetic circuit and when the rotor on the wheel turns it induces inthe sensor, or changes the magnetic
field, and this is fed to the abs processor and of course we all know what happens then ????? Any way
Citroen in Slough told me that one has to fit the same type of sensor on the rear axle, and that the pre
94 model sensor are unobtainable.The point I make is that if one rear sensor gives up the ghost, then its
a case of buying a set, very expensive, GB pounds 74 + vat each. So I did go to the scrap yard and fir
GB 15, got one, and it works, Thanks for all your comments and help.
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The reported change to the ABS sensors, post 1994, (and probably now sourced from the 'corporate
parts bin' and therefore no longer XMspecific?) maybe goes someway to explaining the aleged 'over
sensitive' system on my mk2 estate!
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Regarding the guy with the Mk2 XM with sensitive abs. I would not have thought that the sensitivity of
abs sensors would affect how soon the abs system operates. Surely the system only switches on when
a wheel is skidding ie stopped relative to the sensor.
ABS Warning Light- Mk2 2.0 16v
Any ideas on this one, as 'diagnostics' show that 'no fault' exists!
I have carried out my own 'experiments', and for simplicity, will describe the problem as follows:
On a winter rnorning:
Citroen XM Internet Reference Version 1.0 139
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