A warning in the dash that says, 'front radar unavailable due to obstruction.' the vehicle does this while in motion. The vehicle has 52190 miles on it at this time. The warning will reset when turning off the car and restarting. There are no items obstructed. Nissan dealership stated very common and replacing a lot of them. $1200 is the cost of repair quoted and the service advisor knew that…
2018 Nissan Altima brakes problems
severe 16 complaints filed with NHTSA · avg repair $450 · see brakes across all vehicles →
Failure mileage
Complaints
16
Recalls
0
Avg fix
$450
2crashes
When does it fail?
Of the 16 brakes complaints filed for the 2018 Nissan Altima, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
No new NHTSA brakes complaint has been filed on this vehicle in over 6 years — the issue may be aging out of the active population.
The failure pattern owners describe
Buyer takeaway: Steer clear of 2018 Altimas with automatic emergency braking (AEB) equipped; the front radar sensor fails frequently, generating false braking events at highway speeds that can cause collisions. Brake system responsiveness is also spotty, and Nissan has not issued a recall despite owners reporting the same defects repeatedly.
The 2018 Altima's front radar sensor for the automatic emergency braking (AEB) system is a chronic failure point. Owners consistently describe the dash warning "FRONT RADAR UNAVAILABLE DUE TO OBSTRUCTION" appearing while driving in clear weather with no obstacles present. The system then engages hard braking without driver input—at 25, 45, 75 mph with no vehicle ahead. One driver reported the car lurched to a stop in Manhattan traffic at 25 mph, shaking and skidding; another had it happen twice at 75 mph on a highway. A third was triggered by wind-blown leaves. These incidents create genuine collision risks: drivers behind the stopped vehicle nearly hit them, and one owner had the car physically crash when trying to approach a stop sign.
Separately, several owners report brake pedal failures: the pedal sinking to the floorboard with no stopping power, or sticking so the vehicle won't start without repeated pumping. One owner could not stop approaching a stop sign and hit another car.
Dealers acknowledge the radar issue as widespread—one service advisor quoted repair cost without even looking it up. Sensor replacements under warranty are common early in ownership, but replacements fail again. Out-of-warranty owners face $1,000–$1,200 repair bills. Nissan has not issued a recall despite case numbers assigned and owner requests for one.
Same Nissan Altima brakes reports on nearby years: 2015 · 2019 · 2021
Failure modes owners describe
Front radar sensor malfunction triggering AEB false activation
Front radar sensor reports obstruction when none exists, disabling or triggering automatic emergency braking (AEB) system without driver input. Owners report the vehicle braking hard at speeds ranging from 25–75 mph with no vehicle or obstruction ahead, or braking triggered by leaves and wind. The warning 'FRONT RADAR UNAVAILABLE DUE TO OBSTRUCTION' appears intermittently even on open roads.
When: Reported from 8,500 miles through 59,000+ miles; some issues within weeks of purchase, others after months of ownership
Symptoms owners cite: False 'FRONT RADAR UNAVAILABLE DUE TO OBSTRUCTION' warning on dash; Automatic emergency braking engages without warning or obstacles present; Vehicle pulls to hard stop at highway speeds (25–75 mph) with no vehicle ahead; AEB triggered by leaves, wind, or passing other vehicles on open road; Warning resets after powering vehicle off and restarting; Braking sensation described as slamming brakes or full stop; Vehicle shaking and tire skid during unexpected braking
Repairs/costs cited: Dealers quote $1,000–$1,200 to replace front radar sensor. Owners report sensor replacements performed under warranty early in ownership; repeated replacements with persistent issues after multiple visits. One owner reports dealer stated this is a 'very common' problem they 'see all the time.'
Recalls/TSBs owners mention: Nissan acknowledged complaints via case numbers (e.g., 36978530); declined warranty coverage for out-of-warranty vehicles without paid diagnosis. No recall issued despite multiple owner requests. Dealer stated 'do not have a fix or a recall' for the 2018 Altima.
Brake pedal loss of function and start-up failure
Brake pedal goes to floorboard with no stopping power, or brake becomes stuck requiring repeated pumping before the vehicle will start. Brake sensor failure prevents vehicle start-up or limits vehicle speed to 5 mph after startup.
When: Reported at 36,000 and 59,000 miles; issue recurs intermittently
Symptoms owners cite: Brake pedal sinks to floorboard with no braking effect; Brake pedal stuck requiring pumping to release before car will start; Vehicle will not start unless brake pedal is pumped repeatedly; After startup, brakes remain stuck and vehicle cannot exceed 5 mph; Vehicle may not move at all after complete stop
Repairs/costs cited: Dealer diagnosed faulty brake sensor; vehicle repaired. Owner reports dealer unwilling to repair until diagnostic code is generated, which may take time to appear.
Recalls/TSBs owners mention: Manufacturer made aware (case filed); no general recall or warranty program mentioned for this issue.
Brake system unresponsiveness during emergency stopping
Brake system fails to stop the vehicle or responds sluggishly during emergency braking, resulting in collision or near-collision. One owner reported brake pedal depression had no effect and extended stopping distance, leading to a crash.
When: Reported at 59,000 miles and in another case at unspecified mileage
Symptoms owners cite: Brake pedal pressed but vehicle does not stop; Extended stopping distance approaching stop sign; Multiple brake applications with no effect ('slamming' brakes with no result)
Repairs/costs cited: Dealer investigated but could not find brake failure on inspection. Vehicle was not yet repaired at time of complaint filing.
Recalls/TSBs owners mention: Manufacturer made aware and assigned case number; no resolution or recall noted.
Check engine light and potential catalyst converter issue
Check engine light illuminated with diagnostic code related to catalyst converter. Owner noted auto parts store flagged a recall for this issue on the make and model, though not reflected in Nissan's official channel.
When: Mileage and timing not specified by owner
Symptoms owners cite: Check engine light illuminated; Catalyst converter diagnostic code
Codes mentioned: Catalyst converter code (specific code not stated)
Repairs/costs cited: Code cleared; has not recurred yet but owner anticipates return.
Synthesized from 16 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 1 most recent
Had brakes trouble with your 2018 Nissan Altima?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the brakes problem on the 2018 Nissan Altima?
It's a meaningful issue. 16 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $450.
At what mileage does the brakes typically fail?
Across the 14 complaints that reported odometer mileage, most brakes failures cluster between 11,996 and 37,300 miles, with the median around 25,000. A quarter of owners report trouble before 11,996; a quarter make it past 37,300. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $450 for brakes repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to brakes?
No active recalls currently cover brakes issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2018/Nissan/Altima.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.