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CraigTee's avatar
CraigTee
Explorer
Aug 02, 2013

TPMS on TOAD?

OK.. guess I might need a 21st century primer on TPMS. I totalled my old PT Cruiser TOAD a couple weeks ago and am now in the process of setting up my new(er) one for towing behind my rig.

Last summer I blew a tire on the Cruiser while towing it but luckily had a nice gentleman advise me of it before I damaged the rim.

My replacement Cruiser has factory TPMS.

Is it possible to monitor the Cruiser's TPMS system from within the motorhome while towing? Does somebody make add-on receivers so I could monitor the Cruiser tire pressure from the motorhome?

I've tried to research this but, so far, it just isn't making any sense to me yet. Maybe I just don't have a concept of how TPMS works.

Anyway, thanks in advance for any info on this topic.

Craig
  • Hi Dutch... I pretty much agree with you on all points with the exception of "most economical". The MOST economical would be to tap into the dash indicator for a TPMS fault, wire it into an unused terminal on my connector, and rig up an LED for the coach dash. Total cost about 5 bucks in wire and LED if there's enough amperage coming through to light the additional LED. If not, then I'd need to add a couple more bucks for a small relay.

    Four extra sensors (that don't interfere with existing factory TPMS) would cost me 150 bucks according to the big RV supply house. Since I don't already have TPMS on my coach (1999), I would also need to add another 250 bucks or so.

    So it's kinda no contendre' on that front.

    The other obstacles you bring up can most likely be overcome without a great amount of difficulty. For example... since deciding to change gears on this I've learned a little more about the specific system used on PT Cruisers:
    1. Only used on Cruiser years 2008-2010.
    2. It's a VDO system.
    3. Valve stem type sensor/sender.
    4. Transmits data to the tire pressure monitor WCM and EVIC
    5. Is a simple unit, not differentiating one wheel from another.

    and, a GREAT general description on the overall operation of this unit:

    "The PT Cruiser’s tire pressure monitoring system (TPMS) is unusual in that it does not specify how many tires are low or where they are located.

    The TPMS consists of sensors that are attached to each wheel through the valve stem mounting hole, a central receiver module (CRM) and an indicator lamp.

    The CRM also can include a Remote Keyless Entry (RKE) receiver, Remote Start and the Sentry Key Immobilizer (SKIM) receiver. All receivers share a number of components.

    The CRM decodes the signals sent by each tire pressure sensor. The data is used to determine if a “warning” or “fault” condition exists within the TPMS. Transmissions occur once every minute at speeds of 15 miles per hour or higher.

    If the TPMS detects that pressure in any tire has fallen, the indicator lamp will illuminate."

    So... if I wanted a bit more sophistication, I would shop a scrap yard for a junk wireless control module to install into the coach. The only required connectors SHOULD be power, ground, and dash light output. The unit itself would automatically synch with the Cruiser sensors simply by product design.

    But, I would have to purchase the additional WCM before I could actually test the range. (to determine if I would need to buy a "TPMS range extender" which is another 50 bucks)

    All this makes the simplest and least expensive solution appear to be the most attractive... running the wire from the Cruiser indicator to the coach dash.

    or... is my reasoning unsound somewhere? If so... I am always willing to do more legwork in an attempt to accomplish my goal as opposed to discussing reasons why something WON'T work. That's always my VERY last resort. :)
  • The OEM TPMS vary by manufacturer and even model. Some models, usually lower end, do not use a transmitter/receiver setup at all, instead relying on speed differences and other parameters from wheel to wheel as sensed by the ABS and other sensors. Designing and producing a remote monitor that could be used with a variety of different frequencies and coding methods for those models that do use a radio based system would be costly, and have a limited market. Buying four extra sensors for an existing RV TPMS makes much more economic sense.
  • Thanks to all for taking the time to offer their thoughts and experience on this. It's given me something to think about.

    Being a bit of a minimalist, I really like the idea of using my existing factory transmitters in a solution. I guess I need to research the hardware that the PT uses to receive that signal from the tire.

    Is it built into the vehicle's "computer"?
    Or is it a separate receiver that switches on that little dash light?

    If it's separate:
    Can I get another one from a junk yard and wire it into my coach?
    Would it have enough range?

    If the "receiver" is built into the "on board computer":
    Can I run a wire from the PT dash indicator light to a light/buzzer mounted on my coach dashboard?
    (The PT TPMS "receiver" would have to be able to function with the ignition key in the ACC position)

    If an aftermarket unit could utilize factory sensors in the towed vehicle while adding additional sensors for the coach, I'd just do that instead. Otherwise it may be worthwhile to play with this a bit.

    Again, thanks to all who replied.
    If anybody has played with a DIY solution to this I'd be interested in hearing about that too.
  • If you decide to install the aftermarket monitoring to your toad, you will probably have to have metal valve stems installed. Sometime you can "get away with" using the original stock rubber ones, but sometimes you can't!
  • We, like Brett above, also use a 10 sensor Pressure Pro. Our 2011 GMC Terrain does indeed have its own TPMS, but like others have said, can't find a way to monitor it in the mh. The PP works just fine, I just have to remember to remove the sensors from the toad whenever we stop for a lengthy period of time. I do worry about them when we go out to eat at a restaurant or other places in the public when we are not in the immediate area.

    Ron
  • As others have suggested, you will need to add a second TPMS to your toad-- from from the toad vehicle's factory and an additional one that you can monitor from the motorhome.

    We have the 10 sensor Pressure Pro on ours-- been working fine for 3 years.
  • Right now, no you can't do that. People have been talking about it for a few years but no way to do that now. Adding a system like the TST system
    TST would allow you to monitor the toad while the vehicle is within range of the motorhome and will not impede the operation of the factory PT system when the vehicle is being used.
  • I have factory tpms on the sonic.

    In order to read the Sonic tire pressure, etc, I installed an independent TPMS. I use TST, and so far works great, a lot more peace of mind.

    Do not know of a way to use the factory installed TPMS to monitor the Sonic.

    I don't want to tow a fireball down the road, if I lose a tire on the Sonic for any reason. JMHO.
  • So far I haven't heard of any system that will read the factory TPMS. Every manyfacturer has their own system and you will have to add an additional unit to your valve stem on the PT.

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