Speed sensor

A vehicle speed sensor measures how fast the transmission's output is turning and converts that rotation into the electrical pulses the car's computer reads as road speed. The speedometer reading, an automatic gearbox's shift points, the cruise control, and inputs to systems such as ABS and traction control all come from that one signal.It screws into the gearbox tail housing on most cars that have one, sometimes into the differential, and on many it's driven by a small plastic gear inside the case. It isn't a wheel speed sensor. The VSS reads the whole car's speed at the transmission, and it belongs mainly to older cars, since many newer models calculate speed from the ABS sensors at the wheels and don't carry a separate VSS at all.When a vehicle speed sensor goes bad, the car loses track of how fast it's moving. The speedometer needle wanders or dies, an automatic shifts late and hard or holds one gear, cruise control refuses to engage, and a code such as P0500 or P0720 is stored in the computer's memory.The usual causes are stripped teeth on the plastic drive gear, gearbox oil creeping up the wiring, a connector gone brittle with age, and metal debris collecting on the magnetic tip. Common warning signs:

• A needle that bounces or drops to zero: The signal is cutting in and out, most noticeable at motorway speed.
• A speedometer that never moves: No signal at all, from the sensor, its gear, or its wiring.
• Harsh, late, or missing gearchanges: An automatic timing its shifts from a speed it no longer knows.
• A gearbox stuck in one gear: Limp mode, with the transmission protecting itself from bad data.
• Cruise control that cuts or won't set: The system can't hold a speed it can't read.
• Faults that come and go over bumps: Usually the loom chafed through rather than the sensor itself.

Parthunt24 collates used speed sensor listings from industry leading car parts marketplaces such as Ovoko, ProxyParts, eBay, TotalParts, Opisto, Ecooparts, Ricambipro, and Autoparts24 into one place. Compare 14 offers on vehicle speed sensor price, plug type, and mounting, then click through to the marketplace once one fits.

Most of these sensors look alike, but the differences matter.The plastic gear on the sensor's nose is cut for one axle ratio and one tyre size, so a sensor with the wrong tooth count fits perfectly but reads wrongly, and only the OEM number reliably confirms the count.Gearbox type decides much of the rest. Manual, automatic, CVT, and dual-clutch boxes each take their own sensor, two-pin and three-pin units aren't electrically interchangeable, and the mounting, bolt-down or twist-in, must suit the hole in the case. It's also worth checking how your own car measures speed before spending anything, because a model whose ABS sensors do the counting has no VSS to replace.Set your car in the panel at the left edge, and only sensors made for your gearbox stay in the list. Open any of them and the original marketplace loads, with the seller's description and the checkout.

• Vehicle make, model, and year: Speed sensors change at facelifts even where the gearbox does not.
• OEM part number: Carries the tooth count and calibration that photos can't show.
• Engine type and engine code: Engine and gearbox pairings decide which sensor was fitted.
• Transmission type: Manual, automatic, CVT, and dual-clutch boxes take different sensors.
• Connector type: The plug has to click into your loom, latch and seal included.
• Number of pins: Two-pin and three-pin sensors work differently and don't swap.
• Sensor mounting style: Bolt-down flanges and twist-in bodies aren't interchangeable.
• Driven or non-driven axle configuration: Where the car measures speed depends on its drivetrain layout.
• ABS compatibility: Some cars read speed from the ABS sensors and have no separate VSS.
• Condition of the sensor and connector: Broken teeth, cracked plastic, green pins, or a flat O-ring end it.

Once you're on the original listing, a couple of details matter more than the rest.The photos worth having show the drive gear with every tooth whole and the connector with every pin straight, plus an O-ring that still looks thick enough to keep gearbox oil in.Then check the rest of the advert:

• Photos: The gear end, the plug face, the O-ring, and the number on the body.
• Seller reputation: Steady sales over years, with recent buyers reporting parts as described.
• Compatibility: OEM number and gearbox code together, since the number carries the tooth count.
• Included components: With its O-ring and retaining bolt, or the bare sensor?
• Condition: Chipped teeth, oil inside the plug, cracked housing, a flattened seal.
• Testing: Spun by hand with a meter on the pins, or read live before removal.
• Warranty and returns: Sensible here, since a weak signal only shows on the road.
• Shipping: Small but with a fragile nose, so it should travel padded and gear-end protected.
• Documentation: The donor gearbox code and the car's mileage.

If the teeth, pins, and number all check out, click through to the original marketplace to buy vehicle speed sensor and O-ring from the same seller.

A used speed sensor is among the cheapest electrical parts on a car, and the gear on its nose sets most of the difference.A plain used sensor for a widespread model costs about €5-€25, one with its drive gear and seal €25-€60, and sensors for rare gearboxes or older cable-driven setups €60-€120.On Parthunt24 the lowest vehicle speed sensor price currently sits at 5.00. What moves the speed sensor cost between listings:

• Gear included: A sensor with the correct gear fitted saves a second search.
• Pin count and type: Three-pin powered sensors bring more than simple two-pin ones.
• Gearbox rarity: Common gearboxes mean plenty of donor sensors, and rare boxes the opposite.
• Condition of the teeth: An unworn gear is the whole point of the part.
• Connector state: Clean, uncracked plugs earn their premium.
• Tested or untested: A live reading taken before removal is worth paying for.

Sort by vehicle speed sensor price, compare each listing against the rest, and the best offer for your gearbox stands out at once.

A dead speedometer has more suspects than one, and half of them are cheaper to check than to replace. After a vehicle speed sensor replacement, clear the stored codes with a scan tool, and note that some newer cars want a short drive while the gearbox relearns the signal. While you're at it, check over these on Parthunt24:

• Wiring harness: The loom chafes where it bends, and a bare wire can look exactly like a dead sensor.
• Instrument cluster: Where the needle lives, and its stepper motors fail with the same symptom.
• ABS sensor: The wheel-end sensors that newer cars read their speed from instead.
• Gearbox: The housing the VSS screws into, with the drive gear inside it.
• Drive shaft: Turns the wheels the sensor is counting, and clicks on full lock when its joints wear.
• Wheel bearing: The magnet ring the wheel-end sensors read is built into it on many cars.
• Wheel hub: Often sold with that bearing and ring already pressed in place.
• Wheel hub spindle knuckle: One kerb strike here can disturb the sensor gaps at the wheel end.

Before paying for anything, wiggle the sensor's connector with the ignition on. If the speedo twitches, the fault is in the plug or the loom rather than the sensor.

A speed sensor search shouldn't take more than a few minutes, but it often does. First you have to work out whether your car has a gearbox VSS at all or reads speed from its wheel sensors. Then you trawl listings that don't say which type they are, order the wrong one, and wait again while the return goes through. Parthunt24 removes most of that. Tell it the model and it shows every VSS for sale that actually suits your car, with plugs, tooth counts, and prices in one column.Ordering your speed sensor online happens on the seller's own marketplace, and Parthunt24 adds nothing to the price.Compare vehicle speed sensor prices across the page, and take the lowest one that fits your gearbox today.