Prime Voodoo

That is vastly too long. My 2012 LIftback starts getting pressure readings within seconds of power-up, and normally has all four tires within a minute or so. My fast leak was alerted in time to cross all lanes from the HOV (left) side and safely take an upcoming exit. If the Prime takes much longer, then it is a major step backwards.

After two valid leak alerts each, and several seasonal tire swaps where I forgot to immediately reprogram the sensor codes, I'd describe my 2012 Prius and 2014 Forester TPMS systems as equivalent. It would be disappointing if the Prime doesn't hold up to prior Prius standards.

My Prius has been suffering infrequent false alarms the past 18 months, on both seasonal wheel sets. That drove me to get the updated ScanGauge-II firmware that displays the TPMS readings, which is how I see how quickly and frequently the TPMS readings are received. The basic false alarm is from a wheel not reporting for too long a period, e.g 10-20 minutes. (ScanGauge shows the last reading received, or -14.5 if no reading received since powerup. If an actual reading is showing, I can see the offending wheel not changing pressure while the others do. When a new different reading is finally received, the car's TPMS light instantly turns off.) When it happens, it is sporadic all day, then doesn't repeat for weeks.

The real cause, whether car side or sensor side, is not yet determined, other than I narrowed the summer problem down to a single wheel ID. The winter set has one wheel ID as a prime suspect, but it has not repeated enough to be certain.

 

Ok my fur is starting to go up. Have you done any testing, found any documentation, or is this all just your "sense"?

How did you settle on "30 minutes", for example?

 

About a month ago, when I powered up the Spark for the ride home, a warning light and a message popped up telling me the left front tire was low on pressure. The display also said it was down to 18 lbs. pressure. I pulled the tire and it had a screw in it, so I got the tools and put a mushroom plug in it.

I would imagine some programming would give you the same info from the TPMS that the Spark gives you.

 

@HPrimeAdvanced do you have window tint; there's some mention in Owner's Manual that it might interfere with TPMS sensor reception, page 599 in pdf.

 

After I swapped summer tires to my snow tires it didn’t show the low tire light until 30 mins or so later. Yeah not scientific that’s for sure. It will detect a slow leak, which it did do for me with a small screw. But if the leaks are faster you may hear it before the tpms light goes off.

 

After your tire swap, that wasn't a low tire indication. Instead, it was a sensor-not-detected indication. They have different delay times.

Low pressures are reported as soon as read, which should happen at fairly short intervals. But in case interference or poor reception is causing some sensor readings to be missed, the car gives a considerable grace period to allow for a better read before it triggers the no-sensor indication.

 

That's correct. My swapped summer tires with TPMS are sitting in the shed only a few feet away from where I usually park my car. Every morning my car starts with TPMS lights off even though I have snow tires and wheels with no TPMS on the car. After driving ~20 miles, the TPMS start to blink and stay lit... Until I come home to a park near the shed again. LOL

I never tested it, but it would be easy enough to test how quickly OEM TPMS respond to loss of air in any tire by just letting air escape while on the car. I do think it is an instant response.

 

That's a somewhat different condition though, the tpms sensors are missing, not present and signalling a low pressure. I'm in the same boat btw, notice the same thing each fall when changing over to our snow tires.

The bees knees test would be to have someone watch the dash while you let air out of a tire. I suspect it would report much faster, if not instantly, just considering it's purpose.

After posting I read the above, see I'm kinda flogging the proverbial horse. And sorry for barking earlier.

 

Bad luck, what kind of tires, any aggressive neighbors?
Is it a Hernia repair?

 

Yes, it's an old axiom... The sum of intelligence on the planet is a constant; the population is increasing. If I remember correctly, it's called Cole's Axiom.

 

Dang, I don't know how I missed this thread. Very sorry to hear about the flat and the crash. Dang it!

 

I'd buy some lotto tickers ASAP. Your luck has to make a U-turn!

 

To add insult to your situation now they will be sticking you. Hope things go or went well.

 

Glad it went well. And that you're back!!