CITROEN XM Internet Reference page 140

The brakes 93 ABS sensors
Start vehicle, ABS warning light extinguishes.
With vehicle still stationary, and engine temperature at an indicated 65C, switch off engine and restart.
ABS warning light now remains on.
Still stationary,brakes untouched, and engine now at (indicated) running temperature, switch off engine
and restart. ABS warning light extinguishes.
On a Summer morning (higher ambient temp), ABS light remains on after first starting, but can be
extinguished by restarting, when engine bay up to temperature(as above).
Clearly the fault is related to engine bay temperature, but which component?
If the diagnostics show 'no fault', is the problem in the warning light circuit?
Should I be looking for a relay somewhere?
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The problems I had with my 2 XMs ABS where sensors that needed to be changed ,although
diagnostics didn't show any faults. After changing sensors I never had problems again. Engine bay
temperature may not have anything to do with it.
ABS out of use
Can anybody help with this ABS query: I keep getting the "ABS Out Of Use" message on about 90% of
my journeys (started baout 4 days ago). But it sometimes doesn't come on for 30 odd minutes or so,
sometimes it's only after a couple. It seems to happen mostly in the hot weather we're having at the
moment- it didn't happen last night when I was driving around midnight. Could it be because my brake
pads are getting near replacement time? Or is it more serious?
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Your abs problem is most likely a wheel sensor playing up. These are checked after car starts rolling. To
test disconect connector and use a test meter to verify there is circuit. Front sensors go often about £80
new or go to breakers.
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