Why a TPMS is worth the investment for every RV traveller.
Tyres aren’t cheap, so imagine how you’d feel if one, or more, were completely written off on their first trip. If you’re like us, you’d probably be quite peeved, especially when a serious blowout could have potentially been avoided with a reliable TPMS. But what is a TPMS? Let’s look at them in more detail as a DIY installation project, and explore how this type of system can help protect your rubber.
WHAT IS A TPMS?
TPMS stands for Tyre Pressure Monitoring System, and it’s basically a set of sensors that keep an eye on your tyre pressures (and sometimes temperatures) while you drive. You get alerts in the cabin if something’s not right, so you know before things go pear-shaped.
This is particularly important when towing a caravan or trailer, when you might not feel something is awry until it’s too late, and a punctured tyre has worn down to the rim – potentially costing you big bucks. There are a few types of TPMSs on the market, with some fitted by the manufacturer, and others that you can buy aftermarket.
HOW THEY WORK
The system uses sensors with batteries that are fitted to your wheels and tyres to measure pressure and temperature. From here, the readings are wirelessly transmitted to a receiver display inside the vehicle cabin. In some cases, brands also enhance the signal using additional aerials installed under the vehicle.
The driver can then monitor tyre conditions in real time on the display, which can also be set with alarms to alert you to changes in pressure or temperature.
However, getting a good signal in your vehicle isn’t always easy, especially if you have tinted windows, solar shades on windows, or a heap of gear packed inside the vehicle. The carbon black in window tint is especially notorious for blocking signals, but we’ll cover how to get around it.
TPMS TYPES – THE PROS AND CONS
Internal TPMS
Pros:
- Hard-wired antennas for increased coverage
- Not easily damaged
- Can be programmed individually
- Capable of monitoring up to 16 tyres
- Accurate tyre temperature readings
Cons:
- More expensive than external kits (about $400 on average)
- Antenna mounted on the vehicle
- Cable installation required under the vehicle and up into the dash
- Individual sensors need to be completely replaced when the battery goes flat
External TPMS
Pros:
- DIY installation
- Cost effective (about $249 for an Oricom unit)
- Easily transferrable between vehicles
- No cable installation required
- Repeaters available for better signal (brand specific)
Cons:
- Sensors are exposed to damage or loss
- They have a weaker RF signal (without a repeater)
- Tyre temperatures aren’t always accurate as they’re affected by the external environment
TPMS Components
A number of components make up the system, starting with the way they’re fitted to the rim – either externally or internally.
EXTERNAL
These sensors simply screw onto the valve stem in place of the cap. And if you’re thinking they could easily get pinched, there are anti-theft options available. The downside? They can get knocked off on rough tracks and are exposed.
INTERNAL
The internal style uses a clamp-on sensor inside the rim, meaning it’s way less likely to get knocked off or lost. Like external sensors, they’re powered by a lithium battery, but you must remove the tyre to replace it.
ANTENNAS/RF BOOSTERS
Not every kit comes with antennas, but most brands offer them as optional extras. These are fitted under your vehicle to help pick up sensor readings. Some simply boost the radio signal to reach the monitor in your cabin, while others use cables and splitters to connect straight to the display.
Using a mix of antennas and cables can help overcome the carbon black issue with window tint. This also helps eliminate signal dropouts, which can happen if you’re relying on radio signal alone, and are more prevalent if you’ve got trailer tyres that are further away from the driver’s display.
DISPLAYS
Displays can differ, but their main job is to show you real-time pressure and temperature for each tyre, letting you know if anything changes. They generally run on a 12V system or using solar power.
Simply set them up with your preferred pressure and temperature limits, and an alarm sounds if any readings move outside those thresholds. The fancier models can track more than just your four road tyres, letting you set different alerts for trailer tyres too.
INSTALLATION
As strong advocates for TPMS systems in general, our latest project for a vehicle and caravan used an Oricom external set that monitors up to 10 tyres. In addition, we opted for Oricom’s repeater unit to boost the signal strength and eliminate any chance of sensor dropout due to the vehicle’s tinted windows.
This kit uses screw-on valve sensors, each pre-set for its tyre position. For example, FL for front left on the vehicle, and A1 to A4 for the trailer. The kit comes with dust shields, lock nuts and an angle spanner to help make fitting them easy. Every sensor keeps an eye on tyre pressure and temperature in real time, sending updates straight to the in-cabin display.
To set up the Oricom TPMS repeater, we hooked it up to a 12V power source between the vehicle and trailer. It’s waterproof and small, so we could either pop it on the trailer’s A-frame or near the vehicle’s 7-pin plug.
Once powered, the signal from the tyre sensors gets boosted enough to reach the display inside the cabin. With both the repeater and sensors working together, we didn’t have to worry about weak signals from trailer tyres struggling to make it all the way to the driver’s display.
Downloading an app via a QR code for the manual helped us to set up alarms and limits for each tyre. That way, we could choose when to be notified with a beep and see which tyre was playing up via the flashing display. Overall, it was a quick DIY project, and we were up and running in no time.
WORTH THE INVESTMENT
Getting a flat tyre is never fun, especially if you’re stuck out bush and don’t realise until it’s too late. Having an internal or external TPMS helps provide peace of mind by showing real-time information, no matter where you’re driving.
It could easily be the difference between a quick fix and waiting ages for help… and we certainly know which option we’d prefer.
