A cracked bumper cover after a parking-lot tap looks like a cosmetic problem right up until the blind spot warning quits working. Tucked behind that plastic, usually in the rear corners, sits a small radar module that a $40 fender bender can knock out of alignment or crush outright. When a customer rolls in asking why the light in their mirror went dark, the conversation almost always turns to money next.
So let me lay out honest numbers. I have replaced and calibrated these modules on everything from a base Corolla to a loaded F-150, and the spread is wider than most people expect.
Key takeaways
- A single blind spot radar module runs $300 to $900 in parts, with luxury brands pushing higher.
- Labor to swap one sensor is usually 1 to 2 hours, or roughly $150 to $350 at independent shops.
- Calibration after replacement often adds $100 to $400, and skipping it leaves the system unsafe.
- A cheap aftermarket sensor that will not calibrate is the most expensive mistake I see.
What you are actually paying for
The part everyone calls a “blind spot sensor” is really a small 24 GHz or 77 GHz radar unit. Two of them, one per rear corner, watch the lanes beside and behind you. They are not cameras, and they are not the parking sonar dots. That distinction matters for price, because radar modules cost more than the ultrasonic sensors people confuse them with.
When one dies, you are paying for three separate things: the module itself, the labor to reach it, and the calibration that teaches the car where the new part is aimed. Leave out any one of those and the repair is not finished.
Good to know
If you want to understand what these modules do before you pay to replace one, our explainer on how blind spot monitoring works behind the bumper walks through the hardware in plain terms.
Parts cost by brand
Radar module pricing tracks pretty closely with what the brand charges for everything else. Mainstream Japanese and domestic modules sit on the lower end. German and premium units climb fast, partly because the dealer is often the only reliable source.
| Brand tier | Module part cost | Notes |
|---|---|---|
| Toyota, Honda, Mazda | $300 to $550 | Often available aftermarket |
| Ford, Chevy, Hyundai, Kia | $350 to $600 | BLIS and BCW units, mostly OEM |
| Subaru, Nissan | $400 to $650 | Subaru rear radar runs high |
| BMW, Audi, Mercedes, Lexus | $600 to $1,100 | Dealer-only on many years |
Those figures are for one module. If both corners took damage, which happens more than you would think in a rear-end collision, double the parts and add a little labor. I once quoted a 2020 Lexus RX owner $1,900 just in parts for the pair, and that was before calibration.
Watch out
A bargain module from an unknown seller may be a different part number for a trim you do not have. If the VIN-specific software cannot handshake with it, the sensor will never calibrate and you eat the cost. Match the part number, not just the shape.
Labor: what a tech charges to swap it
Reaching a rear-corner radar usually means dropping part of the bumper cover or pulling a wheel-well liner. On most sedans and crossovers that is a 1 to 1.5 hour job. Pickups and body-on-frame SUVs can run longer if the module lives behind a heavier fascia.
At an independent shop billing $110 to $160 an hour, plan on $150 to $300 in labor for a single sensor. Dealership labor rates commonly land between $160 and $220 an hour, so the same job might read $250 to $400 on their invoice.
- Confirm the fault is the module, not wiring or a blown fuse, before authorizing parts.
- Ask whether the quote includes calibration or lists it separately.
- Get the part number in writing so you can verify it is VIN-correct.
- Check whether one shop can do both the swap and the calibration under one roof.
That first bullet saves people the most money. I have seen more than one “dead sensor” turn out to be a chafed harness or a corroded connector, a repair a fraction of a full module.
Calibration: the fee people forget
Here is the part that surprises drivers. Bolting in the module is not enough. The car has to relearn the exact position and aim of the new radar, a process called calibration. Get it wrong and the system either cries wolf constantly or, worse, stays quiet when a car really is beside you.
An uncalibrated blind spot radar is not a working safety system. It is a light that lies to you.
Some brands calibrate dynamically, meaning a tech drives the car on a specified route while the scan tool watches the radar learn. Others need a static setup with targets and a level floor. Either way, expect $100 to $400 depending on brand and equipment.
Tip
If your warning light came on without any collision, do not assume the module is dead. A blind spot system unavailable message is frequently just dirt or ice on the bumper, and cleaning it costs nothing.
Real-world total examples
Rolling parts, labor, and calibration together, here is what recent jobs actually cost my customers.
A 2019 Toyota RAV4 with a Blind Spot Monitor fault after a rear tap: $420 module, $180 labor, $150 dynamic calibration. Out the door near $750. If you drive one of these, the Toyota Blind Spot Monitor light guide is worth a read before you pay anyone.
A 2021 Ford Edge with BLIS not lighting: $520 module, $220 labor, $120 calibration, roughly $860. A 2020 BMW X3 was the eye-opener at about $1,650 once dealer parts and static calibration were done.
Good to know
Insurance often covers module replacement when the damage came from a collision. If your bumper took a hit, get the sensor written into the claim rather than paying out of pocket later.
How to spend less without cutting corners
You can trim this bill honestly. Start by ruling out the free fixes: dirt, snow, and a stuck setting fool the system all the time. Our roundup of what blocks blind spot sensors covers the usual suspects, and a proper blind spot sensor cleaning has saved plenty of drivers a needless module.
If the module truly is dead, price a quality OEM-equivalent part against dealer pricing, and ask an independent ADAS shop for a calibration quote. Independents with the right scan tools often beat dealer calibration fees by a wide margin.
For the full picture of what these dashboard alerts mean and when they signal a real repair, keep our guide to blind spot monitoring warning lights handy. And if you want to sanity-check whether a repair is even needed, the independent testing summaries at the IIHS driver assistance resource explain how these systems are meant to behave.
The honest range for a complete, calibrated blind spot sensor replacement lands between $450 and $1,700, with most mainstream vehicles finishing around $700 to $900. Know which of those three costs you are being charged for, insist on calibration, and never let a suspiciously cheap module talk you into a repair that will not hold.
Questions drivers ask
Calibration teaches the car the exact aim and position of the new radar module. Without it the system can miss vehicles or trigger false alerts, so most shops charge $100 to $400 for it as a separate line item.
You can physically swap the module in an hour or two, but you cannot calibrate it without a brand-capable scan tool. An uncalibrated sensor is not a working safety system, so most DIY jobs still need a shop visit.
A quality OEM-equivalent part can save money, but it must match your exact VIN-specific part number. A mismatched bargain module often refuses to calibrate, which turns a cheap part into a wasted purchase.
If the module failed because of a collision, insurance usually covers it as part of the bumper repair. Get the sensor and its calibration written into the claim rather than discovering the cost after the fact.
A complete, calibrated replacement on a mainstream vehicle usually lands around $700 to $900. Luxury brands with dealer-only parts and static calibration can reach $1,700 or more.
