Electric Power Steering (EPS) Repair
Summary: Electric power steering fails in a few recognisable ways — a wheel that suddenly goes heavy with an EPS lamp lit, assistance that cuts in and out, steering that fades once the car is warm — and each points to a particular unit: the column, the rack, an electro-hydraulic pump or the control module. We repair your original unit on the bench and send it back tested under load, with a Lifetime warranty.
Our power steering repair service covers every make. Know the symptom? Start with the table. Know the car? Go to the make and model index.
Which EPS unit has failed? Match the symptom to the repair
Steering faults get described in the same handful of ways. What differs is the unit behind the symptom, and that decides what comes off the car.
| What you notice | What it usually points to | What to send us |
|---|
| Steering suddenly heavy; EPS or steering lamp on and staying on | The control module has switched assistance off after a fault in the torque sensor, the assist motor or its own electronics. Only the mechanical link is left. | The assembly the module is built into — the column on many superminis and small hatchbacks, the rack on larger cars — or the module alone where it is separate. |
| Assistance drops out and returns; the lamp clears after a restart, then comes back | An intermittent fault: usually the torque sensor signal or the module’s electronics failing only in certain heat or vibration. A poor connection or weak supply gives the same pattern. | Rule out the battery and charging system first. If both are sound, send the column or rack and note when the drop-outs happen. |
| Fine from cold, heavy after a long run or a string of parking manoeuvres | Heat. The system trims assistance to protect an overheating motor or module. A healthy unit only does this under extreme use; doing it on ordinary journeys points to motor wear or heat-sensitive electronics. | The column, rack or electro-hydraulic pump your car uses, with a note of how far into a drive it starts. |
| Pulls to one side or will not self-centre, with tyres and alignment already checked | Uneven assistance: the torque sensor is reading a twist that is not there, so the motor pushes one way. It feels like an alignment fault and is not one. | The column or rack carrying the torque sensor. |
| A whine that rises as you turn, heavy when hot, and a fluid reservoir but no belt-driven pump | An electro-hydraulic pump: an electric motor driving a hydraulic pump, common on PSA, BMW Mini and Vauxhall models. Motor wear shows as noise first, then fading assistance. | The pump assembly. |
| Knocking over bumps or free play at the wheel, with no warning lamp | Mechanical wear in the rack or column — the one row where the electronics are probably not to blame. | The rack or column, with the knock described on the repair form so it is assessed alongside the electronics. |
| EPS lamp on straight after a battery change, flat battery or jump start | Often no failed unit at all. Many cars lose their steering-angle reference when the supply is interrupted and flag a fault until it is recalibrated. | Nothing yet. A garage can recalibrate the steering angle with a diagnostic tool; if the lamp returns afterwards, go back to the first two rows. |
What the table cannot do is read your fault codes, or tell a sensor fault from a module fault inside the same housing. That is bench work, and it is why we ask for the whole assembly the module is built into.
How electric power steering decides how much help to give
Electric power steering replaced the belt-driven hydraulic pump on most modern cars. An electric motor adds effort only when you turn the wheel, which saves fuel and weight — and makes the steering depend on electronics a hydraulic system never had. Three parts do the work:
- The torque sensor measures how hard, and which way, you are twisting the wheel. Everything else depends on its reading.
- The control module combines that reading with road speed and steering angle and decides how much assistance to give — most at parking speeds, far less on the motorway.
- The assist motor delivers the effort to the column or the rack, or on electro-hydraulic systems drives a small hydraulic pump.
Where the motor sits separates the designs below, and it decides which part comes off your car.
The EPS units we repair
| Unit | Where it is fitted | What typically goes wrong |
|---|
| Column EPS | Motor and module on the steering column behind the dashboard — the usual design on superminis and small hatchbacks | Control electronics and torque sensor faults; assistance that cuts out or goes heavy when warm |
| Rack EPS | Motor and module on the steering rack, low at the front of the car — common on larger and premium models | Module and motor faults, stored assist codes, and sensor faults brought on by heat and moisture |
| Electro-hydraulic pump (EHPS) | An electric motor driving a hydraulic pump under the bonnet — many PSA, Mini and Vauxhall models | Motor wear, whining, heavy steering when hot, a pump that cuts out |
| Standalone EPS module | The control unit as a separate box, where the maker has not built it into the column or rack | Total or intermittent loss of assistance; communication faults with the rest of the car |
Why a failing EPS module feels like a worn rack
The control module is the only part of the system that can switch assistance off, and it is built to do exactly that the moment it stops trusting its own readings.
It constantly checks that the torque sensor, the motor position and the current being drawn agree. If they stop agreeing, assisting by the wrong amount — or in the wrong direction — would be far more dangerous than not assisting at all. So the system drops to the one state it knows is safe: no assistance, a lit lamp and a stored fault code.
Heat and low voltage get a similar response: many systems trim or cut assistance to protect an overheating motor or to ride out a sagging supply.
From the driver’s seat, that safe state feels mechanical. The wheel is heavy and can feel notchy, and at parking speed it can seem close to seized. A drifting torque sensor makes the car pull like an alignment fault. Nothing about it says electronics — which is how complete racks and columns get replaced when the fault was in the module or sensor inside them.
Two questions before you agree to a new rack or column. Is a steering fault code stored, and is the warning lamp lit? If both answers are yes, the electronics are the first suspect, and they can be repaired on their own. No lamp, no code and a clear knock or free play point to mechanical wear instead.
What makes electric power steering fail
Most failures trace back to the conditions the unit lives in:
- Heat. Column units sit behind the dashboard; rack units sit close to the engine and exhaust. Years of heating up and cooling down eventually turn a marginal weakness in the motor or electronics into a failure.
- Water and road salt. A rack unit lives low down in spray, and a column unit can take water from a leaking scuttle or windscreen seal. Moisture at a connector or housing shows first as intermittent faults.
- Vibration. A rack takes every pothole directly, wearing on the connections and mountings inside the unit.
- Supply voltage. EPS draws heavy current at parking speeds. A weak battery, a failing alternator or a poor earth dips the supply, which the module reads as a fault.
- Wear. Assist motors and the gearing that carries their effort wear with mileage like any moving part. On electro-hydraulic pumps, motor wear is usually the first thing to go.
Whenever it cuts assistance, the module stores diagnostic trouble codes. The codes are make-specific, but they fall into recognisable families: torque sensor signal, motor circuit or motor position, supply voltage out of range, internal module faults, and lost communication with other modules, usually shown as a U-prefixed network code. Have them read before anything is removed and send them with the unit — they tell us where to start.
Sinspeed · EPS repair by post
Found your row? Book the unit in
Add the make, model, year, symptom and any fault codes to the repair form. Not sure which unit to send? We will confirm it first.
Tested on in-house HIL rigs under heat, vibration and load · Circuit-level repair by in-house engineers · Lifetime warranty
Repairing your original unit instead of buying a new one
A main-dealer fix for an EPS fault is usually a complete new column or rack. On most modern cars that new assembly then has to be coded to the vehicle and have its steering angle calibrated before it works — dealer tooling on top of the part.
Repairing the unit you already have avoids most of that. We find the failure, repair it at circuit level using genuine OE components, and deal with the weakness behind it rather than fitting a like-for-like part that carries the same design flaw. Your own unit goes back, so it keeps the identity your car already recognises.
Many units are plug and play. Where a particular vehicle needs a steering-angle calibration or coding after any steering unit is refitted, we say so before the unit ships, and it is completed as part of fitting. The price depends on the unit and the fault rather than a flat rate, so your quote is for your unit.
Can you keep driving with an EPS fault?
You can still steer. When assistance is cut, the mechanical link between the wheel and the front wheels remains, so the steering does not lock. But the car is harder to control than you are used to — very heavy at low speed — and on an intermittent fault the assistance can drop out or return without warning.
Do not treat it as something to live with. If your car shows a red steering lamp or a message telling you not to drive, stop when it is safe and follow it. Otherwise get the fault diagnosed promptly, and until then leave more room, take junctions slowly and warn anyone else who drives the car.
How the EPS repair service works
- Tell us what the steering is doing
The repair form asks for the car, what the steering does and when, and any codes a scan has turned up. That is enough to confirm which unit comes off.
- Your garage removes the unit and posts it
Column, rack, pump or module, it comes off the car at your end and travels to us by tracked post or courier. A rack makes a bigger parcel than a column; it comes in the same way.
- Reproduced under load, then repaired
Steering faults often hide on a cold bench. Our Hardware-in-the-Loop rigs recreate the heat, vibration and electrical load the unit sees in the car so the fault is reproduced, then our engineers repair it at circuit level in a cleanroom-standard, ESD-safe workshop.
- Calibrated and sent back
Dealer-level diagnostic tools calibrate the unit before dispatch. It returns ready to refit, with a note of any steering-angle calibration or coding your car needs once it is on.
EPS repairs by make and model
Cars that share a steering design tend to share its failure. Each page below covers one model in detail; a car not listed is still covered through the repair form.
Column EPS
Electro-hydraulic pumps
Racks and other systems
EPS guides
These units can be ordered directly from the shop.
Steering columns
Steering racks
The full range, with fitment details, is in the electric power steering section of the shop.
Electric power steering repair: your questions
Do I send the whole column or rack, or just the control module?
Where the module is built into the column or rack, as it is on most cars, send the complete assembly so the sensor, motor and module can be tested together as they work in the car. If your car has a separate EPS module, send that on its own.
My garage says the steering rack has seized. Could it be the electronics?
It can be. When the control module cuts assistance, the wheel goes heavy enough to feel seized, especially at parking speed. If a steering fault code is stored and the warning lamp is on, have the electronics checked before a new rack is ordered.
The EPS light came on after a battery change. Is the unit faulty?
Not necessarily. Many cars lose their steering-angle calibration when the supply is interrupted and flag a fault until a garage recalibrates it with a diagnostic tool. If the lamp returns once that is done, the unit needs looking at.
Will the repaired unit need calibrating after it is refitted?
Often not, because your own unit keeps the identity your car already recognises. Some vehicles need a steering-angle calibration or coding after any steering unit is refitted; if yours does, we tell you before dispatch and your garage completes it as part of fitting.
Sinspeed · columns, racks, pumps and modules
Heavy steering or an EPS lamp? Start the repair here
Tell us the car, what the steering is doing and any fault codes, then post the unit in.
Genuine OE components · Calibrated with dealer-level diagnostic tools · Mail-in, UK-wide
