[Edge]

.....a warning on the instrument panel???? Walking up to the V, I noticed one tire had a slightly larger radial tire “bulge”........sure enough, it has 20 psi. 2 tires have 35 psi and one tire has 34.5 psi.

When I had a nail through one of my tires I didn't get a warning until I started driving the car.

 

[319625]

.....a warning on the instrument panel???? Walking up to the V, I noticed one tire had a slightly larger radial tire “bulge”........sure enough, it has 20 psi. 2 tires have 35 psi and one tire has 34.5 psi.

It registers when in motion i believe when it sees a variance.
Maybe yours isnt calibrated or wasnt after a rotation so didnt flag the change?

When i put my si rims on the wheel shop put like 44psi in mine, it was like cement blocks but never threw any codes on dash.
Then i adjusted did the reset and went on highway just to know myself that it was done right

 

[williamsji]

When I had a nail through one of my tires I didn't get a warning until I started driving the car.

Same experience.

The TPMS in these new gen5s uses a passive monitoring system.. which detects differences in the speed of the wheels turning. So.. until the tires are spinning and the system monitors some threshold of difference among the tires... TPMS won't alert. My experience is this newer TPMS will fire off when the tire is ~8lbs low... but again.. the tires need to spin for a minute or two for the sensor system to fire.

The downside though is you can get a false TPMS alert if road conditions cause one or more tires to move at significantly different rotation speeds (had this happen one time about a month after I acquired my 2017 CRV).

Unlike earlier generation vehicles...there are no longer sensors behind the tire fill valve.. which is why it is important to periodically do a re-calibration of the TPMS system, particularly if you changed any tire pressure during periodic maintenance. On the plus side.. no need to have to replace valve sensors when you get new tires either.

 

[crv383]

Devils in the details.......I should have said when walking up to the V “in the parking lot”, I noticed what appeared be a low tire. Driving home (about 3 miles), I then pulled into the garage, grabbed my digital tire gauge and found 1 tire 15 psi lower than the other 3 tires. Maybe I haven’t driven far enough......but then again, I don’t know long the tire has been low either. I checked pressures a month ago, after the new wheels were mounted.

Do the external Honda sensors go bad???? I’ve replaced all 5 internal sensors on our ‘09 RAV4.☹

 

[JB in AZ]

Devils in the details.......I should have said when walking up to the V “in the parking lot”, I noticed what appeared be a low tire. Driving home (about 3 miles), I then pulled into the garage, grabbed my digital tire gauge and found 1 tire 15 psi lower than the other 3 tires. Maybe I haven’t driven far enough......but then again, I don’t know long the tire has been low either. I checked pressures a month ago, after the new wheels were mounted.

Do the external Honda sensors go bad???? I’ve replaced all 5 internal sensors on our ‘09 RAV4.☹

The TPMS system on the 5TH GEN CR-V uses the ABS sensors to determine the variable between the 4 wheels rotation seeds. I would hope that these don't actually "go bad" !!!

 

[sirwired]

I bought an aftermarket system that replaced the valve caps and sends pressure and temp info to a solar-powered display on the dash. I think it was $30 from Amazon. There are others that use valve stem sensors, and yet others that use one of blank switch areas to house the display.

Much better, IMHO, than the ABS systems.

 

[crv383]

Hey thanks folks for the info.......I pretty much understand how the sensors measure differences in rotational speed vs tire pressure and how they are mounted externally vs internally. I’m just a little puzzled why a 15 psi difference, which would change rotation speed, hasn’t triggered a warning. I can tell it is low just looking at it.

About 3 months ago I got a tire warning. I stopped in a parking lot, walked around the V looking at all 4 corners and all “looked” fine. I re-did the calibration, to turn off the warning message, and drove on home. No warning driving home maybe 4-5 miles. Forgot to check tire pressure......next morning, tire completely flat. Had it plugged/patched and all was good. The current low tire is a different one.

 

[hans471+]

Some years back a requirement was made that required all auto makers to have some sort of system to warn the driver of a low pressure situation. The law did not state how to do it, rather just that all cars must have it. General Motors (where I worked at the time) elected to use the wheel speed sensors as they were already in place and would only need a change in software to make them work. It saved a bunch of money doing this as well as making the system lower cost to build and maintain. A problem with the system is that using wheel speed to detect an under inflated tire is tricky due to all the other things that can and will cause speed variations. This is why you get "false positives" when your tires are actually OK. The vehicle has to only run the test under certain conditions to get a more correct reading. It has to look at the car being driven in a straight line for a certain distance. (you do know you have a steering wheel position input sensfor, right?). You could drive a hundred miles and never have the car operate under the criteria and therefore not have the sensor going off at you. On the other hand you could be just driving down the street and get a fause reading setting off the warning, totlaly by accident! No system is perfect and near perfect systems get very expensive.

 

[jim256]

"The system does not monitor the tires when driving at low speed." in the manual--but no definition of "low", you mention a 3 mile trip, so maybe it never got done calculating at the higher speeds..

 

[crv383]

..........(you do know you have a steering wheel position input sensfor, right?). You could drive a hundred miles and never have the car operate under the criteria and therefore not have the sensor going off at you............

Everybody knows there is a steering sensor......how else is the “lane keep” going to keep you between the lines.

Instead of a false positive, I think I’m getting a true negative. LOL. I’m watching the sidewall “bulge” and monitoring pressure the old fashioned way. Currently tire “true” pressure is 16 psi with “negative” (no) warning popping up. Probably headed to the dealership and at least ask.?‍♂

 

[crv383]

Well I'll be switched, while running around town this A.M. doing errands (multiple stops), I make a 90* turn out of the local supermarket parking lot and halfway thru the turn I get a "DING" audible and "VISUAL" message saying "Tire Pressures Low". Headed straight home (bought ice-cream ), checked all 4 tires......15 psi in the suspect tire, 34.5-35 psi in the other 3 tires.

TPMS still works.......a little puzzling as to the delayed warning, especially when a blind man could see the obvious large bulge in the sidewall of the under inflated suspect tire.

Headed to Discount Tire......best service and best coffee in town.

 

[williamsji]

Well I'll be switched, while running around town this A.M. doing errands (multiple stops), I make a 90* turn out of the local supermarket parking lot and halfway thru the turn I get a "DING" audible and "VISUAL" message saying "Tire Pressures Low". Headed straight home (bought ice-cream ), checked all 4 tires......15 psi in the suspect tire, 34.5-35 psi in the other 3 tires.

TPMS still works.......a little puzzling as to the delayed warning, especially when a blind man could see the obvious large bulge in the sidewall of the under inflated suspect tire.

Headed to Discount Tire......best service and best coffee in town.

TPMS has no eyes or camera.... so it must settle for checking wheel rotation.

Glad to see it finally trigger. Next month.. with the tire fixed and at proper pressure.. TPMS will probably toss you a false positive just to keep you on your toes.

 

[crv383]

In addition to my man law hood raising......do a weekly walk around looking at tire bulges.

 

[Garfy]

I believe that Honda stopped using discrete TPMS sensors in 2015 (at least on the Fit). That was my first experience seeing no actual sensors on the tires. The advantage of not having discrete sensors is not having to replace them periodically when the battery fails as most shops charge about $100 or so for each one installed. The drawback is that the passive pressure sensing system has to see enough of a variance in the wheel speeds to determine that there is a low pressure problem. The person asking why 15 psi would change the wheel rpm, well, essentially the diameter of the tire decreases when it's significantly low in pressure, hence it will send a higher speed via the ABS speed sensors. The drawback is that the compact spare in most vehicles is smaller in diameter than your normal tire so if you get a flat and put the spare on, the TPMS warning light will probably come on as you drive it long enough for it to determine that it's low.

With discrete TPMS sensors, you don't have to drive very far though you have to get the vehicle speed up enough for the sensor to "turn on" from the rotational speed of the tire. Then it will transmit the data to the receiver and thus turn the warning light on.

Instead of walking around the vehicle and looking for the tire "bulge", it makes much more sense to just buy a digital pressure gauge and check each tire when they're cold (before driving the car). I'm certain that most people's eyes aren't "calibrated" enough to see if a tire is 4 psi low or 10 psi high. Digital pressure gauges are relatively cheap nowadays ($20 or so) and are usually accurate to within 0.5 psi.

 

[crv383]

I believe that Honda stopped using discrete TPMS sensors in 2015 (at least on the Fit). That was my first experience seeing no actual sensors on the tires. The advantage of not having discrete sensors is not having to replace them periodically when the battery fails as most shops charge about $100 or so for each one installed. The drawback is that the passive pressure sensing system has to see enough of a variance in the wheel speeds to determine that there is a low pressure problem. The person asking why 15 psi would change the wheel rpm, well, essentially the diameter of the tire decreases when it's significantly low in pressure, hence it will send a higher speed via the ABS speed sensors. The drawback is that the compact spare in most vehicles is smaller in diameter than your normal tire so if you get a flat and put the spare on, the TPMS warning light will probably come on as you drive it long enough for it to determine that it's low.

With discrete TPMS sensors, you don't have to drive very far though you have to get the vehicle speed up enough for the sensor to "turn on" from the rotational speed of the tire. Then it will transmit the data to the receiver and thus turn the warning light on.

Instead of walking around the vehicle and looking for the tire "bulge", it makes much more sense to just buy a digital pressure gauge and check each tire when they're cold (before driving the car). I'm certain that most people's eyes aren't "calibrated" enough to see if a tire is 4 psi low or 10 psi high. Digital pressure gauges are relatively cheap nowadays ($20 or so) and are usually accurate to within 0.5 psi.

Re-read my post #5. As I stated in my OP and post #5, the tire was noticeably low. I don't cary a gauge in my pocket but my 2 eyes told me the tire was low. Maybe I'm a little more observant than some. You are correct, a digital gauge will read within .5 psi.........that's why I stated 34.5 to 35 psi in a couple of my posts.

 

[Pompatus]

I've had 2 TPMS alerts and both times it correctly detected low tire pressure (one was a nail). If I recall the second alert appeared while driving on a residential street.

 

[Golfdonwon]

TPMS is government gone wild. They are not needed. I haven't had a flat tire in 40 years. I do walk around and look at tires once in a while especially on long trips. I also check my tire pressures about every 6 weeks and occasionally have to add a little air. I also get the lifetime rotate and balance and rotate every 7500 miles. I usually then check the tire pressures soon after. They are usually right on. My dealer also checks tire pressures at oil changes. I always check them almost right away. I often have to let some air out then.

 

[crv383]

...........I haven't had a flat tire in 40 years.........

You need to go buy some lotto tickets.

 

[williamsji]

TPMS is government gone wild. They are not needed. I haven't had a flat tire in 40 years. I do walk around and look at tires once in a while especially on long trips. I also check my tire pressures about every 6 weeks and occasionally have to add a little air. I also get the lifetime rotate and balance and rotate every 7500 miles. I usually then check the tire pressures soon after. They are usually right on. My dealer also checks tire pressures at oil changes. I always check them almost right away. I often have to let some air out then.

TPMS is there for when a tire is punctured while driving... not as a replacement for normal periodic check of tire pressure, wear, etc.

TPMS has saved at least one tire for me.. as driving on a near flat tire can sometimes not be perceived all that well with these modern tires and AWD, and doing so pretty well ensures the tire will be destroyed beyond simple tire repair for a nail or screw puncture.

So... no.. it's not a government conspiracy.

I haven't had a flat tire in 40 years.

You really should not have written this.. because you have now taunted Murphy's Law into coming for one of your tires.