Glossary

Complaints and recalls

Complaint

A report an owner files with NHTSA about a problem they think could be a safety defect. NHTSA takes them through its website, its app, its Vehicle Safety Hotline (888-327-4236) and by letter, and publishes them once personally identifying information is removed. A complaint is the owner's account. NHTSA reviews them for defect trends and may contact an owner for receipts or photos, though it doesn't contact everyone.Source: NHTSA's recalls and investigations resource pages and its complaint file documentation.

Component

The part of the car a complaint or recall is filed under, picked from NHTSA's list: "Power Train", "Service Brakes", "Electrical System" and so on. One complaint can name several. The table at the bottom of this page shows every component on the site and what the site calls it.

Safety defect

A problem that creates an unreasonable risk of a crash, or an unreasonable risk of death or injury in one. A recall needs either a safety defect or a failure to meet a federal safety standard, so a failure can be expensive and annoying and still never lead to one.Sources: DOT Office of Inspector General, report ST2023031 (2023), glossary; NHTSA, "Check for Recalls".

Recall

A recall is issued when a manufacturer or NHTSA decides a vehicle or piece of equipment creates an unreasonable safety risk or doesn't meet a federal safety standard. NHTSA says most recalls are started by manufacturers on their own, before the agency gets involved. The manufacturer has to notify registered owners by first-class mail within 60 days of telling NHTSA.Source: NHTSA, "Check for Recalls" (nhtsa.gov/recalls).

Recall number

NHTSA's number for a recall campaign, shown on Diagsheet as something like 18V-663. It's the number to search on NHTSA's site. The manufacturer has its own campaign number for the same recall, and NHTSA's file records both.Source: NHTSA recall file documentation (RCL.txt).

Part 573 report

The defect or noncompliance report a manufacturer files with NHTSA to start a recall. The date NHTSA received it is the date shown next to each recall on this site.Source: NHTSA recall file documentation (RCL.txt).

Remedy

The fix a manufacturer offers under a recall. Federal law lets the manufacturer choose to repair the vehicle, replace it with an identical or reasonably equivalent one, or refund the purchase price less a reasonable allowance for depreciation, and the remedy has to be provided without charge. NHTSA's recall page puts it as repairing, replacing, offering a refund, or in rare cases repurchasing the vehicle.Sources: 49 U.S.C. 30120(a); NHTSA, "Check for Recalls".

The 15-year limit

The free-remedy requirement doesn't apply to a vehicle first bought more than 15 calendar years before the owner was notified of the defect (the limit for tires is 5 years). NHTSA's VIN lookup also leaves out recalls more than 15 years old unless the manufacturer offers more coverage.Sources: 49 U.S.C. 30120(g); NHTSA, "Check for Recalls".

VIN check

Whether your own car is part of a recall depends on its 17-character vehicle identification number, found at the lower left of the windshield and on the registration card. NHTSA's lookup at nhtsa.gov/recalls shows unrepaired recalls for that VIN. It won't show a recall that's already been repaired on your car, and very new recalls can take time to appear.Source: NHTSA, "Check for Recalls".

Do not drive and park outside

Consumer advisories that can come with a recall, recorded in NHTSA's recall file as "Do Not Drive" and "Park Outside". Diagsheet marks a recall with a red Do not drive stamp when NHTSA's recall record for that vehicle carries the do-not-drive flag.Sources: NHTSA recall file documentation (RCL.txt), fields 28 and 29; NHTSA's recalls-by-vehicle data, which carries the same flag.

Technical service bulletin (TSB)

A document a manufacturer writes on how to repair a recurring problem, and shares with its dealers. A TSB isn't a recall.Source: DOT Office of Inspector General, report ST2023031, glossary.

Manufacturer communications

Copies of notices, bulletins and other communications that manufacturers send NHTSA, TSBs among them. NHTSA makes them searchable by year, make and model on its recalls page.Source: NHTSA, "Resources Related to Investigations and Recalls".

NHTSA investigation types

NHTSA's Office of Defects Investigation looks into possible safety defects. Diagsheet shows each investigation's number, like PE21-001, and the two letters at the front give its type. (The two digits after them are almost always the year it opened.) NHTSA aims to finish a defect petition within four months, a preliminary evaluation or recall query within eight, and an engineering analysis within 18.Source: NHTSA, "Resources Related to Investigations and Recalls".

DP: Defect Petition

An interested party can petition NHTSA to open a defect investigation. A DP is NHTSA's review of that request; if the petition is denied, NHTSA publishes its reasons in the Federal Register.Sources: DOT Inspector General, ST2023031, glossary; NHTSA, "Check for Recalls"; 49 CFR Part 552.

PE: Preliminary Evaluation

The first stage of a defect investigation, where NHTSA gathers basic data about a possible defect trend in a group of vehicles, usually including an information request to the manufacturer. It ends either in a closing or in an upgrade to an engineering analysis.Source: DOT Inspector General, ST2023031, glossary and exhibit F.

RQ: Recall Query

An investigation like a preliminary evaluation, opened when NHTSA sees evidence that an existing recall's scope or remedy may not be adequate: the recall might need to cover more vehicles, or the fix might not be working.Source: DOT Inspector General, ST2023031, glossary.

EA: Engineering Analysis

The second, deeper stage of a defect investigation. It can include vehicle inspections, testing, surveys and further information requests. It closes when NHTSA either finds no safety defect that merits a recall or recommends one to the manufacturer.Sources: DOT Inspector General, ST2023031, glossary and exhibit F; NHTSA, "Check for Recalls".

AQ: Audit Query

An administrative investigation into whether a manufacturer met its obligations to NHTSA. The Inspector General describes it as concerned with timely Early Warning Reporting data. Audit queries in NHTSA's file from the last few years also look at safety-standard certification and at how existing recalls were reported and carried out, so an AQ listed on a vehicle page is a check on the manufacturer's process.Source: DOT Inspector General, ST2023031, glossary; NHTSA investigation file.

EQ: Equipment Query

An investigation that reviews recall reports to identify which suppliers and manufacturers are involved in an equipment-related recall.Source: DOT Inspector General, ST2023031, glossary.

Terms used on this site

Problem group

Every complaint filed under a given NHTSA component whose text contains one of a set of words. "Transmission shudders, slips or shifts hard" is one. How the groups are made and checked.

Narrower sheet

A group that sits inside a wider one, such as "Backup camera goes black or freezes" inside the infotainment group. Every report on a narrower sheet is also on the wider one.

Symptom sheet

The page for one problem group on one vehicle, with phrases you can tick to see how many owners described the same combination.

Mileage track and bands

The chart on a vehicle page. Each problem's bar covers the middle half of the mileages owners reported for it, from the 25th to the 75th percentile, and the tick inside it is the median.

Median

The middle value: half the reports are below it and half above. The site uses it for mileages and prices because a few extreme reports can't drag it around the way they would an average.

Years to avoid

On a model page, the model years whose complaints for each year on the road run well above the model's median year, normally at least 1.5 times it, with up to three years named. Model years that aren't at least two years old aren't judged yet.

First-year log

The page a brand-new model year gets instead of a mileage track: complaints month by month from the first one NHTSA received, with recalls marked where they land.

Newest report line

The line near the top of each page giving the date of the newest complaint, recall or investigation behind it and the date the site last checked NHTSA's files.

NHTSA components on this site

Every component name that appears in the complaints behind this site, what Diagsheet calls it, how many complaints name it, and which problem groups draw on it. A complaint that names several components counts under each.

Where these definitions come from

• NHTSA, "Check for Recalls"
• NHTSA, "Resources Related to Investigations and Recalls", including its recall, investigation and complaint FAQs
• NHTSA complaint file documentation (CMPL.txt), recall file documentation (RCL.txt) and investigation file documentation (INV.txt)
• 49 U.S.C. 30120, remedies for defects and noncompliance
• 49 CFR Part 552, petitions for rulemaking, defect and noncompliance orders
• DOT Office of Inspector General, report ST2023031 on NHTSA's defect analysis process (2023)