TPS warning light

[rustfarmer]

Just finished a week long trip--about 1000 miles and since carrying some luggage I upped the tire pressure to 35 psi rear and 34 psi front. After running about 4 hours in speed zones with 80 mph limit the TPS warning light started blinking so we exit and find a air pump and buy a new digital gauge. Tires were all fine and reading 36 rear and 34 front while still warm. After this short stop the light was off so just kept the speed down to 75 and it did not come back on. Next day, light came on again running about 80 so slowed to 70 and it went out. Tire pressure was still fine. My question is, could the light be coming on from tires being over-inflated? Or could the sensors be old and failing?

[NV Zeno]

A flashing TPS light indicates a SYSTEM problem, not necessarily tire pressure.  How old is your car?  It is possible the TPS sensors in one (and eventually all) of your wheels has croaked or is weak. The batteries that operate them have a finite lifespan.

Just my 2 bucks

[idosubaru]

On 6/23/2022 at 6:15 PM, rustfarmer said:

Just finished a week long trip--about 1000 miles and since carrying some luggage I upped the tire pressure to 35 psi rear and 34 psi front. After running about 4 hours in speed zones with 80 mph limit the TPS warning light started blinking so we exit and find a air pump and buy a new digital gauge. Tires were all fine and reading 36 rear and 34 front while still warm. After this short stop the light was off so just kept the speed down to 75 and it did not come back on. Next day, light came on again running about 80 so slowed to 70 and it went out. Tire pressure was still fine. My question is, could the light be coming on from tires being over-inflated? Or could the sensors be old and failing?

It's almost always tire pressure or a failing tire sensor.

Check to make sure there are no recalls or TSB's about reprogramming the TPMS for your year/model

Is there an aftermarket sensor in any of the tires?  I've seen good results with aftermarket but it would be expected for them to have higher failure rates.

I highly doubt this is the case but if you're speculating 80 mph is a causation and not a correlation: The only physical way I could see speed causing this is if on insanely hot roads with over pressure tires - the heat soak at 80 mph causes the pressure to just exceed the range expected by the TPMS. 

I think it more likely that a TPMS sensor battery is just at the cusp of failing and performing worse at those higher speeds/G forces.