Corsa-B.uk - Vauxhall, Opel and Holden Corsa B Owners Club

its one of the most common problems by far with the Corsa EPS
usualy manifests its self as car pulls to one side or steering wheel is heavy one direction and light the other
in some cases it can be fixed, other require a replacment steering rack
bit of a guide on how to fix:

Tools Required:
Medium sized Phillips screwdriver, T2.5 Torx bit, flexible driver,
small 2BA or 1/4" ring spanner, 13mm ring spanner.

Turn the Steering wheel to expose the two pop-on screw covers on the
retaining screws for the steering column switch covers, remove the
covers and the two phillips screws underneath. Remove the three
phillips screws underneath the lower steering column switch cover and
remove the cover. Remove the fuse cover and take out the two screws
beneath the fuse box to allow the lower section of the dash to be
pulled away.
On the lower right hand side of the steering column assembly just
inside the dash, there are two torx screws holding the steel cover
plate that protects the torque sensor. Remove both of these using the
flexible driver and T2.5 torx bit. Remove the cover. Before
proceeding, mark the position of sensor body relative to the steering
column body.
If you only need to reset the torque sensor position, you need only
loosen the screws to allow adjustment. If you need to fix the
sticking steering problem then the sensor must be removed. The torque
sensor is retained with two more T2.5 torx screws. The lower
retaining screw can be accessed fairly easily by pulling the lower
right section of the dash away from the metal structure. The upper
one is more difficult and may be slackened using the torx bit in a
small ring spanner.
Next, turn the steering column to gain access to the bolt that
secures the lower steering column universal joint to the rack spigot
that projects up through the floor. Remove the retaining bolt and
swivel the joint away.
If you have a short piece of plastic drain pipe or a cardboard tube,
slide it over the universal joints so that the steering column is
free to turn without jamming on anything (like your hands).

BEFORE TURNING ON THE IGNITION, READ ALL OF THIS BIT!.
When the ignition is turned on and the engine started, the EPS will
drive the steering column depending on reading of the torque sensor.
If you do this now, there is a chance that the wheel will be driven
continously in one direction. The column has a position sensor at the
top behind the steering wheel that will count 30 turns from end to
end before it jams. Check this before proceeding. Then turn the wheel
back to centre (15 turns from one extreme).
Now be ready to turn off the ignition if the next step causes the
wheel to spin rapidly. Turn on the ignition and start the engine. The
steering may spin rapidly, Switch off if it does. Rotate the torque
sensor fractionally and turn on the engine again. Repeat this process
until the steering is still when the engine is running.
Then, give the steering wheel a short tug in one direction and let it
settle, then do the same in the other direction. The wheel may
continue a little or might bounce back a little. If necessary adjust
the torque sensor position until the behaviour is identical in both
directions.
Now switch off, and check the steering centre position by counting
the turns, and reset it in the central position.
Repeat the torque sensor setting procedure to ensure that the
behaviour is identical in both directions. Adjust if necessary. When
you are satisfied that the steering is balanced and neutral turn off
the ignition, and tighten the sensor retaining screws.

Refit the Sensor cover, re-assemble the lower universal joint, refit
the covers and screws and test drive