2012 Honda CR-V AWD: TPMS False Alarm
October 17, 2012
It was a brisk morning in Tonopah, Nevada and the other two vehicles in our convoy had already left the parking lot. "I have a blog photo to take in front of this mural," I said. "You guys go on ahead. I'll catch up."
Just after they got out of radio range I noticed that the 2012 Honda CR-V's TPMS light was ablaze. "Oh, expletive," I muttered, thinking back to the large number of small stones that had been strewn along the gravel roads we'd been on the previous day.
Nothing looked out of sorts, as is often the case at times like this, so I whipped out my gauge and checked all four tires to see which one was low. The recommended pressure according to the CR-V's door jamb sticker is 30 psi all around. My trusty gauge read 30 psi on three of them and 29.5 psi on the other.
Basically, there was no problem. This was a false alarm. The typical TPMS trigger point is 25% below the recommended tire pressure, so the light should not have come on unless the tire pressure was down to 22.5 psi or less in one of the tires.
Why the false alarm? I have no clue. The overnight temps were in the low 40s, and Tonopah sits at 6,000 feet, but my gauge reading made sense in the same circumstances.
So I drove on, confident that the light would extinguish itself in 10 or 15 minutes.
Why that long? Well, the sort of TPMS the CR-V has, the kind that doesn't have wheel position intelligence, transmits a pressure reading to the central computer every three minutes or so. In order for the light to go out the computer needs to see a string of similar readings -- typically 4 or 5 -- before it gains enough "confidence" to extinguish the light. Three minutes times 4 or 5 readings works out to 12 to 15 minutes.
And so it was. The light went out as expected about 12 miles down the road and it hasn't come back on since.
I could get irritated by this, but that impulse disappears when I think back to all the times TPMS has saved our editors the hassle and potential peril of a roadside flat or blowout. I'm OK with the occasional flakey reading if the worst thing that happens is I get out my gauge and check the tire pressures when maybe I don't really need to.
Of course the operative word here is "occasional." Once a month I could handle, because we all should be checking our tires at least that often anyway. But I'd be pissed if this happened several times a month. We'll keep an eye on it.
Dan Edmunds, Director of Vehicle Testing @ 9,152 miles