A decade ago, a blowout case started with a shredded tire on a flatbed and a reconstructionist with a tape measure. The driver said the tire failed. The defense said the driver drove on it flat. Both sides argued over tread depth, heat marks, and whatever a witness remembered.

Today, the first thing a careful attorney asks for isn’t the tire. It’s the tire pressure monitoring log sitting inside the vehicle’s electronics, and the sensor history on the wheel itself.

The log answers the question the tire can’t: what the pressure was doing in the minutes, hours, and sometimes weeks before the tread came apart. If you’ve been hurt in a crash involving a tire failure, that data is often the quietest, strongest piece of evidence in the file. It also has a short shelf life.

What Is a TPMS Actually Recording?

Every passenger vehicle sold in the US for roughly the last two decades carries a tire pressure monitoring system. Under FMVSS No. 138, the system has to warn the driver when a tire drops meaningfully below the manufacturer’s recommended cold pressure. That warning is the part drivers notice. The data behind it is the part lawyers care about.

Direct TPMS setups put a sensor inside each wheel that reports pressure and temperature by radio to a module in the vehicle. Indirect systems infer low pressure from wheel-speed differences. Either way, something is logging a stream of readings, flagging anomalies, and often timestamping when the warning lamp came on and when it went off. On many newer vehicles, that information is retained alongside the event data recorder’s crash snapshot.

Why Does This Matter in a Blowout Case?

Tread separations and blowouts almost never happen out of nowhere. Underinflation and heat work on a tire for a long time before it comes apart. If the sensor history shows a slow leak over three weeks and a warning lamp that lit up two days before the crash, that changes who is responsible, and it changes what the case is worth. 

For anyone weighing a claim, calling a personal injury lawyer early is often what gets the preservation steps moving before the data disappears.

A few of the common scenarios the log can clarify:

• Driver-ignored warning. The lamp came on days earlier and nobody addressed it. That’s a comparative-fault argument the defense will press hard.

• Recent service. A tire shop rotated or replaced tires the week before. Pressures and sensor IDs in the log can show whether the work was done to spec.

• Fleet or rideshare vehicle. The log can reveal that a company vehicle was dispatched with a known low-pressure warning active, which shifts attention to the employer.

• Manufacturing or design claim. A tread separation at correct pressure, confirmed by the log, points away from the driver and toward the tire or vehicle maker.

Who Gets to Pull the Data?

The vehicle owner has the clearest claim to it. But after a serious crash, the vehicle is often in a tow yard, an insurer’s custody, or a salvage auction pipeline. That’s where cases get lost. Once the battery sits dead long enough, or the module is pulled, or the wheels are separated from the car and scrapped, the sensor history and the stored warnings can disappear.

Preservation is a legal step, not a mechanical one. An attorney can send a spoliation letter to the tow yard, the insurer, and any repair facility, demanding that the vehicle, the wheels, the tires, and the electronic modules be held in their current state until a qualified expert can download them.

Isn’t the TPMS Light Enough on Its Own?

The dashboard lamp tells the driver something is wrong. It doesn’t tell a jury when, how low, for how long, or which tire. The underlying log can. On a direct system, you can often see pressure readings tire-by-tire over time, the moment a threshold was crossed, and the ambient conditions around it.

Pair that with the event data recorder’s snapshot of speed, braking, and steering input in the seconds before impact, and reconstructionists can tell a coherent story: the right rear was losing a pound a day for a month, the warning fired on the morning of the crash, speed held steady at highway speed, and the separation happened on a hot afternoon. That’s a very different case from “the tire blew.”

What Should You Do in the First Week?

1. Don’t let the vehicle be released. Tell your insurer in writing that the car, all four wheels, all four tires, and the TPMS and EDR modules must be preserved. Repair, salvage, and total-loss processes move fast.

2. Photograph everything on scene if you can. The failed tire, the debris pattern, and the dashboard warning lights before the vehicle is shut off.

3. Get the service history. Receipts, rotation records, and any prior low-pressure complaints. A forensic tire investigation depends on this paper trail alongside the sensor data.

4. Loop in counsel before the adjuster calls back. Preservation letters carry more weight when they go out early, not after the vehicle is already at auction.

A tire failure case used to come down to arguments about rubber. In part, it still does. But the opening exhibit now is the record the vehicle kept on its own, and the side that gets to that record first tends to control the story the rest of the case tells.