jlsoaz
Posts: 602
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

tpms question

Sat Feb 17, 2018 6:10 pm

Hi -

background to question:

Recently I ran into opposition to a suggestion I made that gm should improve aspects of its tpms so that it would be more hassle free. This was prompted by my own experience:

- apparently the dealer provided the vehicle to me without it having been checked to verify if the tires had been registered properly (or whatever the process is called).
- this didn't really come out until it became clear that I had a tire with an issue, but it was displaying at the wrong position on the dashboard, and I was struggling at gas stations to verify which tire to fill.
- In the end, I checked with the dealer twice, and it does appear that many of the dealer visits that folks have to them have to do with tire pressure.
- However, it's not clear from what little I was told that this is because there is something wrong with the system. In some (or possibly many) cases this may be because increased awareness of tire pressure being off may lead to customers simply wanting the dealer to bring the tire pressure into line.

Question:
- I can't remember from my Leaf experience 2012-2015: are there many or any situations where Leaf tire pressure presents for the the wrong location of the tire? also, are there many situations where a mechanic will forget (or not have the right tool to hand) and the pressure of multiple tires will be incorrect on the dash?
- Do other vehicles (whether or electric or otherwise) have this issue?
- is it inherently expensive and difficult to clear this up in designing a tire pressure monitoring system?

What I am getting at is that in my view anything that leads to a lot of dealer visits to me constitutes hassling the customer, whether from the neglect of a mechanic on a simple task, or from something else. So, I suggest that if there is a way to revise tire pressure monitoring so that it is less prone to reporting incorrect numbers/locations, for whatever reason, that this be done. However, I don't know if there is something inherently expensive to the matter (one person has suggested this) or if it is just a matter of approaching the matter differently from an engineering/design standpoint and it can be addressed without that much difficulty.
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/batteries/leaf/vehicle.php?vid=229
2017-October: bght 2013 Volt
will buy 150+ mile BEV when they become less expensive on used market
josh@jlaz.com
opinions expressed are my own

GerryAZ
Gold Member
Posts: 1708
Joined: Mon Nov 22, 2010 6:47 pm
Delivery Date: 12 Jun 2011
Location: Phoenix, AZ

Re: tpms question

Sun Feb 18, 2018 1:36 pm

2011 through at least 2015 LEAFs do not display individual tire pressures on the dash. There is a procedure in the service manual to register the positions. Leaf Spy Pro displays the four pressures and has a way to activate the programming procedure. Different cars have different methods to register positions (some require test equipment, others do not). My 2004 SUV came with a donut-shaped magnet. After rotating tires, the owner simply selects sensor registration on the menu of the console display, places the magnet over the valve stem of the left front tire and waits for a horn chirp, then moves clockwise around the car waiting for a horn chirp at each tire. My experience with both of my vehicles that have TPMS is that tire shops and dealers do not take the time to register the positions after performing work.
Gerry
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015

jlsoaz
Posts: 602
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: tpms question

Sun Feb 18, 2018 4:19 pm

GerryAZ wrote:2011 through at least 2015 LEAFs do not display individual tire pressures on the dash. There is a procedure in the service manual to register the positions. Leaf Spy Pro displays the four pressures and has a way to activate the programming procedure. Different cars have different methods to register positions (some require test equipment, others do not). My 2004 SUV came with a donut-shaped magnet. After rotating tires, the owner simply selects sensor registration on the menu of the console display, places the magnet over the valve stem of the left front tire and waits for a horn chirp, then moves clockwise around the car waiting for a horn chirp at each tire. My experience with both of my vehicles that have TPMS is that tire shops and dealers do not take the time to register the positions after performing work.


Thanks Gerry, this gets me partway there.

You say "...Different cars have different methods to register positions (some require test equipment, others do not). ..."

Are you saying that some cars just automatically get everything right (positions, tire pressure) without the owner (or mechanic) having to do anything such as possess a special tool? Or perhaps they get more things done automatically than the cars that require a separate tool, but everything is not automated (the mechanic still has to remember, that sort of thing).

In an age of amazing smart phones and ever-faster super-computers, it seems at first glance a bit odd for a vehicle designer not to be able to have a car display tire pressure and position correctly on a dashboard without the vehicle mechanic or the owner/operator having to do anything. Maybe there's something that I just don't understand as to what is physically necessary for the system to work.
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/batteries/leaf/vehicle.php?vid=229
2017-October: bght 2013 Volt
will buy 150+ mile BEV when they become less expensive on used market
josh@jlaz.com
opinions expressed are my own

lorenfb
Posts: 1760
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: tpms question

Sun Feb 18, 2018 7:53 pm

jlsoaz wrote:Are you saying that some cars just automatically get everything right (positions, tire pressure) without the owner (or mechanic) having to do anything such as possess a special tool?


Yes, as an example Porsche vehicles automatically "learn" the position of each TPMS after replacement within a five mile drive.
There's no need to use any external device or test equipment. One just uses the steering column controls to enter the
TPMS "learn" mode.
Leaf SL MY 9/13: 65K miles, 50 Ahrs, 5.2 miles/kWh (average), L2 charges to 100% > 1000, max battery temp < 95F, min discharge point > 20 Ahrs

jlsoaz
Posts: 602
Joined: Sun Jul 08, 2012 12:57 pm
Delivery Date: 10 Oct 2012
Leaf Number: 24218
Location: Southern Arizona, USA

Re: tpms question

Sun Feb 18, 2018 9:24 pm

lorenfb wrote:
jlsoaz wrote:Are you saying that some cars just automatically get everything right (positions, tire pressure) without the owner (or mechanic) having to do anything such as possess a special tool?


Yes, as an example Porsche vehicles automatically "learn" the position of each TPMS after replacement within a five mile drive.
There's no need to use any external device or test equipment. One just uses the steering column controls to enter the
TPMS "learn" mode.


Hi - thanks for the additional info.
Former lessee 2012 SL
http://www.pluginamerica.org/surveys/batteries/leaf/vehicle.php?vid=229
2017-October: bght 2013 Volt
will buy 150+ mile BEV when they become less expensive on used market
josh@jlaz.com
opinions expressed are my own

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