Electrical · Morden SM4

ABS Sensor Replacement for Morden and St Helier

Our workshop is about 12 minutes from Morden, past Morden Hall Park and down through Mitcham to Hackbridge. We read the ABS fault codes, test the wheel speed circuit and find the real cause, and ABS sensor replacement starts from £89.

Get an instant price Call 020 4629 9469

★★★★★ 4.9/5 from 87 Google reviews
~12 min from Morden
Mon–Sat 8am–8pm

Audi SQ5 in for brake and wheel-speed work at KITH Cars Garage & Bodyworks, Hackbridge

ABS Sensor Replacement for Morden drivers

St Helier Avenue, traffic calming and wheel speed faults

St Helier Avenue is a wide dual carriageway that now has a 30mph limit, with a 20mph limit at the Rose Hill roundabout at its southern end. It still invites steady speed, and at the Morden Hall roundabout, a busy multi-exit junction, traffic can bunch suddenly. That's where ABS and stability control quietly do their job, keeping the wheels turning under hard braking so you can steer. With the ABS light on, both are switched off.

Off the main roads, the St Helier estate's long, straight avenues have parked cars and traffic calming, and the town centre around Morden Underground station is dominated by buses and crossings. Years of humps and potholes put strain on wheel bearings and the sensor wiring that runs along the suspension. Many cars here are family estates and people carriers with plenty of miles on them, and on those, corrosion around the sensor or a bearing with play are the most common causes of an ABS light.

We diagnose rather than guess. The ABS module tells us which wheel has lost its signal and what type of fault it has seen. We then compare live wheel speeds, test the sensor circuit and check the bearing and the ring the sensor reads. If the magnetic encoder is built into the bearing seal and it's damaged, we'll explain why a new bearing is needed and give you a written quote covering exactly that.

The route is Morden Hall Road to the Morden Hall roundabout, then Morden Road (A239) east past Morden Hall Park into Mitcham, Cranmer Road and Carshalton Road south to Hackbridge, about 4 miles. With only the ABS light showing, the car is usually fine to drive carefully, though we'd keep speeds modest on the dual carriageway. If you'd rather not drive it, collection can be arranged. Repairs come with our 3-month workmanship warranty.

Electrical

ABS Sensor Replacement: what’s involved

Each wheel has a speed sensor that reads a toothed or magnetic ring turning with the hub or driveshaft. The ABS module constantly compares the four signals. If one wheel slows too quickly under braking, the system releases and reapplies that brake to stop it locking. The same signals feed traction control, stability control and often the speedometer, hill-hold and tyre pressure warning.

Older cars use passive sensors that generate their own signal. Most modern cars use active sensors, which are powered by the ABS module and often read a magnetic encoder built into the wheel bearing seal. Sensors sit right next to the brakes, exposed to heat, water, salt and brake dust, so corrosion, damaged wiring and failed connectors are common. When a signal drops out, the system switches ABS and stability control off and lights the warning. Your normal brakes still work.

From £89Written quote first

45 minutes–2 hoursTypical time in the workshop

3 monthsWorkmanship warranty

4.9★87 Google reviews

Signs of an ABS sensor fault

ABS warning light on

A steady ABS light means the system has switched itself off. Normal braking still works, but the wheels can lock under heavy braking.

Traction and stability lights too

Because they rely on the same wheel speed signals, the traction control or ESP light usually comes on with the ABS light.

Light comes and goes

An intermittent warning, often after bumps, in wet weather or at a certain speed, usually points to damaged wiring, a loose connector or a corroded sensor.

ABS pulsing at low speed

If the pedal pulses and the ABS activates when stopping gently, a sensor may be giving a false reading from a dirty sensor or a cracked reluctor ring.

Speedometer or tyre warning faults

On cars that take road speed or tyre pressure monitoring from the wheel sensors, a faulty sensor can upset the speedometer or set a tyre warning.

Other systems disabled

Hill-hold, cruise control, stop-start and some electric parking brake functions may stop working when a wheel speed signal is missing.

When should it be done?

ABS sensors have no replacement interval. They are replaced when they fail or when their wiring is damaged. Get the car checked as soon as the ABS light comes on, because the car won't stop as well in an emergency on a wet road without ABS and stability control. An ABS warning light that stays on is also an MOT failure. Faults often show up after brake, hub or suspension work, when a sensor or its wiring may have been disturbed.

ABS, traction or stability warning light on
Intermittent warnings in wet weather or over bumps
Warning lights after brake, wheel bearing or suspension work
Before an MOT if the ABS light is showing

How we replace an ABS sensor

Check-in and symptomsWe ask when the light appears and whether any work has been done recently, as disturbed wiring after brake or suspension work is common.
Diagnostic scanWe read the ABS module fault codes to identify which wheel is affected and whether the fault is signal, circuit or plausibility related.
Live data and testingWe compare live wheel speed readings on a road test or ramp and test the sensor circuit with a multimeter or oscilloscope to separate sensor, wiring and ring faults.
Inspect the ring and bearingWe check the reluctor ring or magnetic encoder for cracks, corrosion or damage and check the wheel bearing for play, as either can cause a false signal.
Written quoteWe explain the cause and give you a written quote. If the encoder is built into the wheel bearing, we'll explain why the bearing may need replacing.
Replace the sensorWe carefully remove the old sensor, which is often seized in the hub, clean the mounting, and fit the new sensor with its wiring routed and secured correctly.
Clear codes and road testWe clear the fault codes, road test to confirm all four wheel speeds read correctly and the warning lights stay off, and run any calibration the car needs.

Parts we fit

Sensors must match the car exactly. Active and passive types are not interchangeable, and connectors and lengths vary between models and even between axles. We fit OE or OE-equivalent sensors from manufacturers such as Bosch, ATE or Continental. Where the wiring is damaged we repair it properly with sealed connectors, and where the fault is in a reluctor ring or a wheel bearing encoder, we replace that part rather than just the sensor.

OE or OE-equivalent ABS wheel speed sensors
Reluctor rings where cracked or corroded
Wheel bearings with integral magnetic encoders where required
Sensor wiring and sealed connector repairs

How long it takes

45 minutes–2 hours

A straightforward sensor swap often takes under an hour. Seized sensors, wiring repairs or a reluctor ring or wheel bearing replacement take longer. Most jobs are completed the same day.

What’s included

ABS system fault code scan
Wheel speed live data check
Sensor circuit and reluctor ring inspection
Correct replacement sensor fitted
Fault codes cleared
Road test to confirm the warning lights stay off

Getting here from Morden

From Morden to our Hackbridge workshop

From Morden station take Morden Hall Road to the Morden Hall roundabout, then follow Morden Road (A239) east past Morden Hall Park into Mitcham. At the Cricket Green stay on the A239 into Cranmer Road, then join Carshalton Road (A237) heading south over the railway by Mitcham Junction; past Beddington Corner it becomes London Road into Hackbridge, where Soho Mills is near Hackbridge station.

Follow Morden Road (A239) past Morden Hall Park into Mitcham, then Carshalton Road south to Hackbridge, about 12 minutes. With just the ABS light on, drive gently.

Directions from Morden

About Morden

Morden is a suburban town at the southern end of the Northern line, and grew rapidly after Morden Underground station opened in 1926, with its population rising from about 1,300 in 1921 to over 12,000 by 1931. Much of the housing is 1920s and 1930s semis and terraces, including a large part of the London County Council's St Helier estate, laid out along wide avenues and cul-de-sacs. The town centre is compact and dominated by the station and the Crown House civic tower, with generous parks on either side. It is a family and commuter suburb where most journeys are by car or bus to the station, so the few main roads carry most of the traffic.

Places nearby: Morden Hall Park, Morden Underground station, Baitul Futuh Mosque, St Lawrence Church, Morden Park, Morden Park House

Postcodes: SM4 · London Borough of Merton

More about KITH for Morden drivers

Questions

ABS Sensor Replacement in Morden: your questions answered

My ABS light goes off when I restart the car. Can it wait?

Intermittent faults usually get worse, and while the light is on, ABS and stability control aren't working. The fault code is often still stored even when the light goes out, so it's a good time to have it read.

Do people carriers have more ABS problems?

Not necessarily, but heavier vehicles that carry families and luggage put more load through their wheel bearings, and bearing play can upset the ABS signal. We check the bearings as part of our diagnosis.

Can you collect my car from a Morden CPZ?

Yes. Let us know the street and zone, and we'll arrange a collection that works with the parking restrictions. We'll call you with the diagnosis and quote once it's with us.

Is it safe to drive with the ABS light on?

The car will still brake normally, so you can usually drive it carefully to the garage. But without ABS and stability control the wheels can lock under hard braking, so leave extra distance. If the brake warning light is on as well, get advice before driving.

Will an ABS light fail the MOT?

Yes. An ABS warning light that stays on, or doesn't come on when the ignition is switched on, is an MOT failure. The same applies to the electronic stability control warning on cars that have it.

Can I just clear the code?

If the fault is still there, the ABS module will find it again, usually within a short drive. Clearing codes without finding the cause just delays the repair.

Why might I need a wheel bearing as well?

On many modern cars the magnetic ring that the sensor reads is built into the wheel bearing seal. If that encoder is damaged or the bearing has excessive play, a new sensor won't cure the fault, and the bearing has to be replaced.

Why did the light come on after my brakes were done?

ABS sensors and their wiring sit close to the brakes and hubs, so they can be knocked, stretched or left unplugged during brake or suspension work. Sometimes an old sensor that was already corroded fails when disturbed. A quick scan shows which wheel is affected.

Instant quote

Price your ABS sensor replacement now

Enter your reg and we’ll look up your car and price the job from our own labour rates and the book time for your model. Then book it in with a fixed written quote before any work starts.

Free, about 30 seconds, no sign-up
Parts, labour and VAT included
3-month workmanship warranty
Collection from Morden can be arranged

“It’s rare to find a garage you can truly trust. Fair price, brilliant customer service.”Thinushan K. · ★★★★★ Google

Prefer to talk? Call 020 4629 9469 or WhatsApp us.

Loading instant quote…

More for Morden drivers

Brake Repairs in Morden · Wheel Bearing Replacement in Morden · Engine Diagnostics in Morden · MOT Testing in Morden · Car Servicing in Morden · Clutch Replacement in Morden · Accident Repairs in Morden · Tyre Fitting in Morden · Vehicle Recovery in Morden

ABS Sensor Replacement across South London

ABS Sensor Replacement Mitcham · ABS Sensor Replacement Wimbledon · ABS Sensor Replacement Rosehill · ABS Sensor Replacement Sutton · ABS Sensor Replacement Worcester Park
Beddington · Carshalton · Cheam · Coulsdon · Croydon · Norbury · Purley · Streatham · Thornton Heath · Tooting · Wallington