2008 C5, ABS/ESP/ASR system/ Parking brake faulty (Wheel speed sensor error)

[Andy_Silk]

Normal daily driving:
Alarm sound
"ESP/ASR system faulty"
"Parking brake faulty"
"ABS"
"Service"

WTF...? Nooooo...!

When opening car door:
Alarm sound
"ESP/ASR system faulty"
"Economy mode active"
"ABS"
"Service"

When driving:
Alarm sound
"ESP/ASR system faulty"
"Parking brake faulty"
"ABS"
"Service"

When opening car door after loooong parking:
Nothing

When driving after looooong parking:
Alarm sound
"ESP/ASR system faulty"
"Parking brake faulty"
"ABS"
"Service"

Sooo, possibly some wheel speed sensor issue?
Guess?

Went to service guy, error code from Left Rear Wheel Sensor.
(Unfortunately I did not check the error code that time.)

New Left Rear Wheel Sensor was installed.
Part and work 134 euros, not bad.
But... symptoms changed a bit:
When opening door, all the same.
But when starting engine and driving a little bit, all errors goes away.
Just to come back when driving 40+ kmh.

Sooo, sensor and sensor wireing is maybe good all the way to ESP, because sensor/signal is maybe good, because error is erased at rolling start speed, to come back when driving faster.

Soo, whats now wrong?
Guess?

New visit to service guy (AutoCom gives only 5 digits):
C1326, rear left, faulty signal, deviation, permanent
Then removed tyre and brake disk to visually check the parts.

The "possible" culprit in the picture.

Bonus item; wheel bearing was EOL, had a sound, and a couple of mm play, and was hot.

2008 C5 tourer, 350 000 km.

[mickthemaverick]

That looks awful, hopefully you'll get it sorted!!

[aerodynamica]

I had this on the front wheel and ut was not the sensor but was the magnetic ring the sensor reads. Corrosion and it partly fell off. It is part of the wheel bearing and was fixed by a full front bearing replacement.

[Andy_Silk]

That looks awful, hopefully you'll get it sorted!!

Well, if you open the picture, and zoom in really really close, you might be able to see that there is two very very tiny hairline fractures on the magnetic ring.

[Andy_Silk]

I had this on the front wheel and ut was not the sensor but was the magnetic ring the sensor reads. Corrosion and it partly fell off. It is part of the wheel bearing and was fixed by a full front bearing replacement.

Yup, same.
Funny though that the service guy has been working 35 years repairing citroens and said that this was the first time he saw this kind of (magnetic ring) failure.
One reason for that might be that he also said that C5 X7 rear bearings are known to fail, so rear hub will be replaced before it rusts out and magnetic ring fails.

[mickthemaverick]

You may find this of interest Andy : viewtopic.php?p=846175#p846175