powersurge wrote:The TPMS goes on when ONE of them goes below a certain point. That ALERTS YOU that a tire is below pressure, and you should check ALL of them.
That is just because Nissan implemented a dummy-light on the dashboard. The car knows
which of 4 sensors is reporting the low pressure -- in fact, the car knows what the exact tire pressures are. The car just doesn't tell you that because someone decided it's sufficient to just provide a the equivalent of a check engine light ("something is wrong; check everything and see what it is").
A better car interface would show you the four tires and the pressures. Leaf Spy Pro does that - and it's an advantage. Tesla does that on the dash.
I agree the car should show you the actual pressure values. Let me relate two experiences which demonstrate why:
1. I was driving my 3/4 ton truck, towing a travel trailer to our campsite. While crossing the Astoria-Megler bridge, I got a low pressure warning. This bridge is over 4 miles long, one lane each direction, with no shoulder. https://en.wikipedia.org/wiki/Astoria%E2%80%93Megler_Bridge
The point being that if you need to stop and change a tire on this bridge, you will cause a massive traffic jam and probably get a visit from the police. Luckily, the truck showed me all the tire pressures on the display, and I was able to see that I still had safe pressure. I made it across the bridge, and while keeping a close eye on the pressure, drove another 10 miles to my campsite, where I changed the tire safely.
2. We also own a Honda CR/V. While driving Hwy 58 in Oregon at about 4 in the morning, I got a low pressure warning in the middle of nowhere. It was cold and dark, and not safe to pull over. Unfortunately the vehicle does not show the actual pressures, so I had to decide whether to pull over somewhere dangerous, or wait until I hit the next tiny town. The car seemed to handle fine, so I sweated it out and kept going about 15 miles into town. When I got out and measured all the tires, they were all fine, though there was a spread of about 4psi between them. Apparently this was enough to set off the alert. Had I been able to read the pressures while driving, I wouldn't have stopped or worried about it until it was convenient, later in the day. (Equalizing all the pressures and resetting the system is all that was required).
2013 Pearl White SV, bought used in 2017 with only 5100 miles. Vancouver, WA.