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TPMS-203 Tyre Pressure Monitoring System

Review by Laurie Kibblewhite - 4WD Oz DVD

I have had numerous incidents with my caravan over the past few years, where I have lost a wheel, destroyed a rim, and managed to save one by pulling into a rest bay by sheer chance just after one of my caravan tyres shredded itself. I have also had a couple of punctures that we discovered because of a device I was using at the time. It was always a back wheel that was the culprit (I have a tandem axle van).

Now the wheel loss was my fault entirely - didnít check the wheel nuts after a service ..... but the rest .....
I use a Weight Distribution System, which keeps my caravan incredibly stable - even on three wheels - we followed the drag marks 40 kms back along a dirt road trying to locate my lost wheel - never did find it ...... and it was noise that alerted me to the wheel that got destroyed. A twitch going down a hill was also an indication, but all caravans twitch at some stage .......
I installed a Tyre Pressure Management System (TPMS) on my caravan. (basically a car system, but fitted to my van - I figured I would know when my car tyres were going down). It worked with the transmitters fitted inside Dust Caps, and sent tyre pressure and tyre temperature information to a display affixed to the windscreen. It alerted me to two punctures that we got - one in a rest area, and one in a service station, and those two alerts basically paid for the TPMS. However, two caps were destroyed when tyres disintegrated, and the replacement caps were $100 each.
And so for a while (I was also off the road with illness for 18 months) I basically had no warning system on the van. When planning for my current trip, I recalled that I had a tyre go flat on the Kalumburu Road and it was another traveller who brought my attention to it - we were travelling with reduced tyre pressures, and the road being rough, were sliding around a bit anyway. And so I decided to look at what was available, and it was a post on Facebook by another traveller, (I canít remember who it was and canít find the review) that led me to investigate the TPMS manufactured by INAWISE.

I decided that I needed an 8 wheel system, one that covered my car AND my caravan. I found their website (, found my local distributor (Albany Bridgestone Tyre Service - ABTS), and made my enquiries. ABTS had been a distributor for two years and had never had an enquiry, and so handed me the brochure I required, and I headed off to do my homework. I worked out from my experience with my previous system what I needed to know about this unit, and went back to ABTS, who contacted INAWISE and passed on my queries. Eventually, I needed to know a few more technical details, and so ABTS gave me the number of the company, and I spoke to Eddy from INAWISE about my concerns.
The main points were
Does the unit register when you lose a wheel?
How are the transmitters fitted to the wheel?
How much does it cost to replace transmitters?
How long do the batteries last?

There was not a convincing yes to losing a wheel. The company is working on that scenario, but it wasnít perfected at that time.
The transmitters replace your valve stem - they are fitted inside the wheel, and so loss of battery and/or dust cap is not a problem
The figure was quite low - much less than the $100 for my old system
The battery life should be the life of the tyres at least ( and most tyre sets last several years - in my case more often - every couple of years) and so time will tell.

We decided to go ahead with the system, and ABTS were excited when it turned up, to be involved in installing this high tech gear into my wheels. The instruction book came out, and we decided to wire the unit through the cigarette lighter - it can be hard wired. The antenna has a really strong magnet and hangs underneath the car.
Ironically, the day of the fitting coincided with their second enquiry about the system, and the so the enquirer was able to see the system and watch it being fitted.

OK, so how well does it work?

I towed my van home, and next morning came out to my car, and the unit started beeping, and one of the numbers on the display unit was flashing, and the tyre pressure was indicating low........... and so, I checked the tyre, pumped it up, and towed the van back to ABTS, who found the valve stem was loose. They pulled the tyre off and checked the alignment of the sender as they tightened up the stem. All fixed, and no more problems.

We were travelling north, when the beeper took off and I took a few seconds to realise that the TPMS was talking to me, and one of the numbers was flashing. The tyre pressure on one of the tyres was reading high. WHY?

And then I remembered. The unit is factory set at 50 psi, and will tell you if you are 30% over or 20% under that figure. Well, on the van, that was fine, but I had been running my car at 40 psi. And so we had to tell the unit that that was our cold tyre pressure number. This is done by pressing a button at the back of the unit for 5-6 secs, and this resets and overides the factory setting. Fine, except I later set my rear tyres on the car to 44 psi, and when they got hot and increased the tyre pressure to 52psi, the unit told me so. ( 30% of 40 psi is 12 psi, and 52 psi had been exceeded.) And so it meant that I needed to reset the cold tyre pressures.
We were doing a run on dirt roads out of Halls Creek, and so I reduced the tyre pressures to 30 psi, and was again warned by the TPMS that my tyre pressures were below the 20% threshold, and a display reset was required to fix that.
The unit works, and works well.
My only gripe was the display unit itself. It is Green LED lighting behind a dark, glossy convex screen. The book tells you for best results to mount it away from the sun. Being a windscreen mounted unit, that isnít easy to do, and so, during a bright sunny day it is difficult to monitor (even more so when wearing sunglasses,)
I phoned Eddy at INAWISE, and we discussed this. Surprisingly (or maybe not), they have had requests from owner to install a switch to turn the display OFF, and just have the audio working. They found the unit a distraction. Me, I like to see what is happening, and when the warning signal is transmitted, I can see instantly which wheel is having the problem (flashes).
INAWISE are addressing these concerns.

The unit works, it covers ALL of my wheels (and will do up to twelve wheels - it was developed for trucks), and is in my opinion well priced. You only have to save a couple of tyres at $300 each to have the unit pay for itself.

Incidentally, I paid for this unit, and have written the review to alert caravanners that such a system does exist, and works, and in my opinion, is cheap insurance.

FOOTNOTE:   If you are reading my trip blogs on the Savannah Way, you will have noticed that I had a slow leak that wasn't immediately obvious from looking at the tyre. The pressure was set at 40 psi, and once the leak got below that, the TPMS did it's job when I fired up, and let me know that I had a problem, which wheel, and the current pressure. This review was written a number of weeks before that incident.

We had a couple more tyre problems that this unit alerted me to. One was near Winton in Qld, when I obviously ran over something that really whacked the underside of the vehicle. A second or two later, the TPMS started beeping, and inspection revealed that the rear tyre (same one as before as it turned out) was flat. It turned out to be a different problem, a wide cut in the tread of the tyre - possibly a piece of metal, and the tyre was dead.

On my way back to WA, the TPMS watned me again that I had a leaking tyre. I chose to pump the tyre and keep going. It alerted me again next morning. It was certainly doing its job. Turns out that on my diversion to have a look at Ivy Tank (video on YouTube), I managed to stake a tyre, and the twig was still embedded in the wall of the tyre.

Surprisingly, ALL of these tyres were on the car, and the caravan tyres gave me no problems at all.


If you would like to contact me or email your thoughts or comments, please feel free to do so. I would love to hear from you

For more photos, visit Lesley's site. Queensland, Australia

Lesley Bray Photography




Updated 1.9.13