When the electric power steering (EPS) warning light comes on, the assistance often cuts out completely — leaving you with very heavy steering, especially at low speed. It's a safety-critical fault that needs immediate attention.
What the EPS warning actually means
Electric power steering replaces the old hydraulic pump and belt with an electric motor, either on the steering column or on the rack itself, controlled by its own module. A torque sensor measures how hard you are turning the wheel and the motor adds assistance to match. When the steering wheel with an exclamation mark lights up — yellow or red depending on the make — the control module has detected something it cannot verify and has reduced or switched off assistance. The steering still works mechanically. There is a solid mechanical link from the wheel to the road at all times; what you lose is the power part. That matters enormously at parking speeds, where the wheel goes from light to genuinely heavy, and much less at 50mph. It also means a car that feels normal on the bypass can be almost unmanageable in a supermarket car park.
Is it safe to drive?
Short answer: you can drive it, carefully, to a garage — but treat it as urgent rather than something to leave a fortnight. The risks are practical. Effort at low speed can be three or four times normal, which matters most for junctions, roundabouts and emergency avoidance. Intermittent faults are worse than permanent ones, because assistance coming back suddenly mid-corner will jerk the wheel in your hands. Stop driving straight away if the wheel becomes very heavy at speed, if it goes light and vague in one direction, if there is knocking or grinding from the column, or if the fault comes and goes while cornering. Any of those, call recovery. On the MOT: an illuminated EPS or steering malfunction lamp is a failure on cars first used from 2018, and heavy or inconsistent steering is assessed separately as a defect at any age.
Why it usually happens — the cheap causes first
**Low battery voltage.** The most common trigger there is, and the one people never expect. The EPS motor draws serious current, so if the battery is weak or the alternator is under-charging, the module protects itself and switches assistance off. Very often the fault appears at the same time as a flat-battery morning or a jump start. Check charging voltage — 13.8 to 14.6 volts at idle — before spending anything else. **Poor earths and corroded connectors.** Salted UK roads corrode the multiplugs on the column and rack. A green, crusty connector or a corroded earth point causes exactly the same fault codes as a failed motor at a fraction of the cost. **Steering angle sensor not calibrated.** Very common after a wheel alignment, a suspension repair or a battery change. The car needs a scan tool to relearn straight ahead; without that it throws EPS and often ESP and ABS lights at the same time. **Wheel speed sensor fault.** EPS varies assistance with road speed, so it needs vehicle speed data. A failed ABS sensor can knock out the steering assistance as a side effect, which is why EPS, ABS and traction lights so often appear together.
The more expensive causes
**Torque sensor failure.** Built into the column on most cars. Symptoms are assistance that fades in and out, or steering that is noticeably heavier one way than the other. On many models the sensor is not sold separately, so a failure means a full column assembly. **EPS motor or control module failure.** Known weak points include the Vauxhall Corsa D and Astra H column motors, several Fiat, Peugeot and Citroën models, and some Toyota and Honda racks. Water ingress is a frequent root cause — a leaking bulkhead grommet or scuttle drain drips onto the module. **Rack-mounted EPS unit failure** on newer cars, typically the most expensive outcome because the assembly and the rack are one part. One useful point on cost: specialist rebuild firms will recondition many column and rack EPS units for far less than a new part, and a garage can fit a reconditioned unit with the original coding. Always ask for that quote alongside the new-part price.
What a proper diagnosis involves
A generic OBD2 reader will usually show nothing at all here, because EPS codes live in their own module. You need a scan tool that talks to the steering control unit. The sequence a good garage follows: read all module fault codes including steering, ABS and body; test battery condition and charging voltage under load; check voltage drop on the EPS supply and earth; inspect connectors at the column and rack for corrosion and water; view live data for torque sensor output and motor current while the wheel is turned; and check whether the steering angle sensor needs calibrating. Only after all of that should anyone talk about replacing a motor. Expect £45 to £90 for the diagnostic. It is money well spent — the difference between a £70 calibration and a £900 column is entirely down to reading the codes properly.
UK repair costs in 2026
Fitted prices at an independent garage, including VAT: - Diagnostic with a steering-capable scan tool: £45 to £90 - Steering angle sensor calibration: £40 to £90 - Battery replacement and coding, where low voltage was the trigger: £100 to £290 - Connector repair, earth repair or wiring loom fix: £80 to £250 - ABS wheel speed sensor: £90 to £220 - Torque sensor, where available separately: £250 to £600 - Reconditioned column EPS motor fitted and coded: £350 to £750 - New EPS column assembly: £600 to £1,300 - Rack-mounted EPS unit: £900 to £2,000, and more at a main dealer One more thing worth checking before you pay for anything: several EPS faults are covered by manufacturer recalls or extended warranties, particularly on Vauxhall, Toyota and Honda models. A quick recall check on the registration takes a minute and occasionally makes the whole bill disappear.
Making the fault less likely to come back
Keep the battery healthy. More EPS lights are caused by a tired battery than by a failed motor, and start-stop cars are especially fussy. Have it load-tested annually once it is past three years old. Keep water out. Clear leaves from the scuttle drains under the windscreen every autumn — a blocked drain is what soaks the module on a lot of the cars that fail. Avoid holding full lock. Sitting at full lock while manoeuvring loads the motor heavily and some systems cut assistance temporarily to prevent overheating. Wind back a fraction from the stop. And after any alignment, suspension work or battery change, make sure the steering angle sensor has been recalibrated before you leave.
Can I drive with the electric power steering light on? — You can drive it carefully to a garage, but treat it as urgent. The steering still works mechanically, though it becomes very heavy at parking speeds. Stop and call recovery if the fault comes and goes while driving or the wheel feels vague.
Why did my power steering light come on after a flat battery? — Low voltage is the single most common trigger. The steering motor draws heavy current, so the module shuts assistance down to protect itself and logs a fault. Charge or replace the battery, clear the code, and it very often stays away.
How much does electric power steering cost to fix in the UK? — Anywhere from £40 for a steering angle sensor calibration to £2,000 for a rack-mounted unit. Most cases land between £350 and £750 for a reconditioned column motor fitted and coded. Get the codes read before assuming the worst.
Will an EPS fault fail the MOT? — Yes on cars first used from 2018, where an illuminated steering malfunction lamp is an automatic failure. On older cars steering that is abnormally heavy or inconsistent is assessed as a defect in its own right.
Why are my ABS, traction and steering lights all on together? — The steering system uses wheel speed data to decide how much assistance to give, so a single failed ABS wheel sensor commonly triggers all three lights. Fix the wheel sensor and they usually clear together.
Can a normal code reader find an EPS fault? — Usually not. Steering fault codes are stored in the steering control module, which a basic generic OBD2 reader cannot access. You need a scan tool that reads all modules, not just the engine.
Why is my steering heavy one way but not the other? — That points at the torque sensor in the column, which measures driver input in both directions. A drifting or failing sensor gives uneven assistance and is one of the clearest signs of a column fault.
Can water damage cause power steering failure? — Yes, and it is a common root cause. Blocked scuttle drains or a perished bulkhead grommet let water drip onto the steering module or connector. Clearing the drains each autumn is cheap prevention.