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Matt, Mechanical Engineer
Category: Vauxhall
Satisfied Customers: 24209
Experience:  BEng hons Mech engineering, in auto industry 22 years
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2008 vauxhall corsa power steering not working when vehicle

Customer Question

2008 vauxhall corsa power steering not working when vehicle is staionary when you start to drive it graduly starts to work . can that be repared .
Submitted: 2 years ago.
Category: Vauxhall
Expert:  Matt replied 2 years ago.
Hello the steering will naturally get lighter once the car is moving anyway, so I suspect that your power assistance isn't working at all? its a full electric system on this car with a motor on the column thats under the dash1st thing to check is if the fuse for this circuit is intact and it connections are bright and clean If this is Ok then the column motor may need to be replaced but often you can invigorate them as follows:Tools: Medium sized Phillips screwdriver, T2.5 Torx bit, flexible driver, small 2BA or 1/4" ring spanner, 13mm ring spanner.Method: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.2: Random Jamming or "notchy" steering.========================================This fault is caused by the mechanical components that translate the steering column effort (Control Demand) into motion that is proportional to torque. Direction is inferred by the magnitude of the torque being positive or negative. This mechanical translation is managed using a slant-pivot coupling connecting the upper and lower parts of the steering column that operates a sliding collar normally held in a central position by springs. The motion of the slant-pivot coupling is limited, and at either extreme allows direct coupling between the upper and lower sections of the steering column. The torque sensor detects the position of the sliding collar and produces an electrical signal to represent the effort and direction of turning the steering wheel. The EPS system then activates the motor that drives the lower section of the steering column in the correct direction to reduce the sensor reading to zero. i.e. No more turning is demanded.The problem occurs when the slant-pivot coupling or the sliding collar bind or lock at some position in the travel. The components are lubricated when built, but the lubricant degrades over time and eventually hardens and dries where it is thinnest. When the steering is turned slowly or by a small amount the friction at some points is enough to make the coupling bind rather than slide, causing a zero torque reading that effectively removes all power assistance until the coupling moves. To the driver this seems like the steering just got very heavy or jammed for an instant.It is possible to reinvigorate the assembly using a mixture of ordinary gear oil and a molybdenum disulphide based additive such as molyslip or stop smoke.Method:Carry out the same procedure as case 1, then mark the correct position of the torque sensor and remove it.Inject no more than 15cc of the Oil & MoS2 lubricant mixture into the void around the sliding collar and replace the torque sensor carefully. It will be necessary to rotate the sensor until the sensor actuator engages with the sliding collar correctly. Until the sensor is correctly engaged it will fail to seat properly. Do not force it into place or use the screws to try and pull it into position. The sensor arm is biased to one end by a spring and it will have moved when the sensor was extracted. Offer it into place and feel for the situation where the sensor arm spring tension can be detected. When it is in the right position it will just go into place easily and then it can be rotated to the correct neutral position as previously marked.Before replacing everything else, start the engine and check that the steering behaves properly. If it turns in one direction switch off immediately and reset the torque sensor position by following the procedure for case 1.After lubricating the internal components, a few days may need to elapse before the lubricant penetrates all parts of the coupling. Over this time the steering will gradually become lighter and may start to favour one direction as the coupling finds a new equilibrium position. If this occurs it will be necessary to reset the torque sensor position again.
Expert:  Matt replied 2 years ago.
Hido you still need help?Bear in mind that the site takes a deposit from you at the beginning and this is held by the site until you rate my answer at which point the cash is split between the site and the expert. I am only paid for my work on this question if you rate my answer, using the star system at the top of the screen. Please do not forget! Thank you