TPMS External Sensor Setup in Our 4WD
Our external TPMS setup for our 4WD. In this post we show you our OBD2 Australia external TPMS setup in our 4WD. TPMS stands for tyre pressure monitoring system. If you would like to know more about what a TPMS setup is and how it all works, then check out our detailed post here.
What is a TPMS?
A TPMS is a tyre pressure monitoring system for a motor vehicle. We have done a detailed post explaining how a TPMS works as well as the benefits of having one installed in your 4WD. If you want to check that post out then click here out then click here. But in summary, a tyre pressure monitoring system monitors the tyre pressures and temperatures of the tyres on your 4WD. The type of TPMS we are referring to here, is an aftermarket wireless setup for 4WD’s that don’t come standard with one out of the factory. A TPMS setup will usually consist of a display unit and wireless tyre sensors that can be fitted internally or externally. If you would like to read about the pros and cons of both internal and external tyre sensors, then read our post here.
In our 4WD we installed an external TPMS setup. Let’s get into it now.
OBD2 Australia External TPMS
OBD2 Australia TPMSS6 is the tyre pressure monitoring system model that we purchased for a total cost $165. This TPMS setup for our 4WD comes with a solar powered display unit and six external sensors. We chose a six sensor option so that we could use four sensors for our 4WD and the other two for our Drifta off-road touring trailer, DOT373. We chose this system over other brands mainly because we weren’t sure whether or not this was something we would actually want or needed. As a result we decided on buying a cheaper option compared to say an ARB setup which is three times the price.
Our 4WD external TPMS setup was advertised as follows by the supplier:
- Install time of under 10 minutes.
- Range of 25 metres.
- Suited to 130PSI.
- Solar powered display unit with in built battery.
- USB-C port to charge if no solar.
- 6 x external tyre pressure sensors (unsealed).
- Customisable tyre pressure and temperature alarms.
- 2 year battery life on sensors (we got 3 months on a couple).
- 12 month warranty.
- Pressure units in PSI or Bar.
- IP67 waterproof grading.
Fitting the TPMS Display Unit
The display unit is quite small in size, doesn’t weigh much, is made from plastic and has a small display screen with a solar panel on the top side of the unit. Provided instructions are fairly average to be perfectly honest. Installation is not explained well, although it is fairly straightforward. We tried to setup the display unit alarms first which wouldn’t work for us and provided us weird information that did not correspond to the instructions. Turns out you need to fit the sensors first and then you can setup the display unit. This is not clearly stated, but we worked it out eventually.
The display unit is simply stuck to the dash with double sided tape. We fitted this in the centre of the dash where it will get enough sun to keep the display unit battery constantly charged. There is a USB-C port as a backup for charging. We have only used this port twice: once when we first got the unit to fully charge; and another time when we didn’t seem to get much charge from solar for some reason. This hasn’t occurred again though, the battery has remained fully charged since then. There is not much to the display unit, it basically shows you your four tyres, each tyres pressure and temperature. With the six sensor model, the bottom tyres change every 3-5 seconds or so, to show you the other two tyres for the trailer. This is great when towing, but can be a little annoying day to day when you aren’t towing and don’t want it to cycle through the bottom tyres. Would be great if there was an option to turn the cycle off. Either way it is not a big issue at all.
Setting Up Alarms
When setting up the unit, as mentioned above, make sure you have fitted the sensors first. Then you can cycle through the different settings options. You have the ability to set the units as either PSI or Bar as well as degrees Celsius or Fahrenheit. You are also able to setup three alarms for pressures and temperature. There is a minimum and maximum pressure alarm that can be set as well as a maximum temperature alarm. We have our high pressure alarm set at 47 PSI and the low pressure alarm at 10 PSI. The temperature alarm has been set at 70 degrees Celsius (it shows as 80 in the photo but this has since been updated). The idea of the alarms is that you can choose these values and then the unit will set off the alarm if any of these thresholds are passed through.
Fitting the TPMS External Tyre Sensors
The tyre sensors are fairly small in size, and being black are not noticeable when fitted to your tyres. The product comes with a small spanner that you need to use to secure the sensors to your tyres as well as when you need to change the battery. It would be a lot better if the product came with a spare spanner, as it would be a pain if you lost the one that was provided with the set. If you have a really small adjustable spanner then you would be ok in such a situation. We have heard some people only finger tighten these lock nuts and haven’t had any issues, however we prefer to take slightly longer ensuring they are far more difficult to be removed. Fitting the sensors is simple, you basically add one of the locking nuts first, then screw on the sensor, and finally tighten up the locking nut with the provided spanner. The locking nuts help ensure that the sensors don’t come loose as well as make it a bit more difficult for someone else to remove them.
Each sensor is labelled in order to correspond correctly with the display unit. This is because each sensor is pre-programmed to the display unit. Here with the six sensor option, they could have labelled these in a more obvious manner. We found that we got the rear ones the wrong way around with the trailer, so had to swap these. Again the provided instructions could have been a lot better here and explained the labelling of the sensors. There was no legend or key to tell you what the different letters on the rear ones are supposed to mean. If you had the four sensor option then this would not matter as it would be fairly simple, front left, rear right and so on. With a more expensive setup, we would expect the instructions to be far better here however it would not be a big effort to improve these.
Using the Data from the TPMS Display Unit
Once all sensors are fitted, takes less than 5 minutes, and your display unit has been setup, you will see all the different tyre pressures and temperatures displayed on the unit. While driving it is really interesting watching the pressure and temperature changes in different conditions. It is also really interesting seeing how tyres can change quite differently depending on your load, where it is within your 4WD and if you are towing.
The right hand side rear of our Cruiser is slightly heavier, we have tried to offset this on the left hand side, but there is still slightly more weight, mainly due to the spare tyre sitting on the driver side. The driver side rear tyre increases in pressure slightly more than the left hand side tyre. The TPMS setup now allows us to get the cold tyre pressure on this side correct. Now we don’t see such large increases in pressure and temperature compared to the opposite side tyre. When towing the rear tyre pressures will increase significantly more compared to when you aren’t. All that extra weight on the tow ball and rear axle makes a massive difference. As a result we can ensure we get the correct cold tyre pressure in our tyres when we add that extra weight on the tow ball. This is all common sense stuff but it is interesting seeing the changes on the display unit and how much pressures and temperatures can vary in different conditions.
We will note though, that the temperature reading that we have seen don’t seem to be very accurate. We only get readings 5-10 degrees higher than the ambient air temperature. Here we believe an internal sensor would provide you with more accurate temperature readings. That being said, this is not a real big issue for us because if you are running the correct pressures you shouldn’t have any temperature issues. The two are directly correlated, pressures too low and tyre temperatures will increase.
Summary of Our TPMS Setup
It is a fairly simple installation with the external sensor option. It only takes about 15 minutes to be fully setup. This includes playing around with the settings and finding a good spot to mount the display unit. We do like that we can always see our tyre pressures and temperatures at any time. Great for knowing if there is a leak so that we can pull over and fix the issue before doing any damage to our rims and tyres. We always carry a tyre repair kit so any punctures can be fixed quickly before any damage occurs.
Obviously airing up and down will become a longer process with the external sensors fitted. The sensor and the lock nut both have to be fully removed when airing down, if using a fast tyre deflator that needs to screw on. When airing back up, both will again have to be fully removed for our ARB digital tyre inflator to fit onto the tyre valve. We recon it adds at least another 2-5 minutes to this process, so be aware of this if you are going off-road regularly as this might an annoyance for you. In this situation, internal pressure monitors might be a better option.
We also love it that we can calculate the tyre pressure increases as we drive. Then using the 4PSI rule of thumb we can ensure we get our cold tyre pressures correct in all conditions. To read more about the 4PSI rule, tyre pressures and temperatures, then check out or detailed post on how a TPMS works here. But basically this rule which is more of a guide than law, states that if you tyre pressures are changing by more or less than 4PSI after an hour or so of driving, then you need to adjust your cold tyre pressures to reflect a 4PSI change. Another option is to work off around a 10% change however this will probably vary more when you are running very low pressures. If you are seeing more or less then you need to increase or decrease your cold tyre pressures.
The tyre sensors are supposedly using German made chips so you would expect with any German engineering accurate tyre pressure readings. We have found that this is not always the case, we are usually within 1 PSI of our ARB digital inflator readings. Maybe one is more accurate than the other, who knows, but within 1 PSI is not a bad error rate at around 40 PSI (2.5%). Another thing we have found annoying is that the display unit screen is not visible when wearing polarised lenses. This is not a massive issue as I have both polarised and non-polarised sunglasses in the Cruiser, however if you only wear polarised lenses you will need to take them off to view the display units.
The battery life in the sensors is far from the advertised 2-year life span. We have already changed two batteries within three months. The batteries appear to be of average quality, so when replacing the two flat ones we decided to change all of them with far better quality batteries. Again, if buying a better quality setup you would expect that better batteries would come standard however companies are always trying to reduce their costs to increase margins, so be prepared to replace them with better quality ones.
Is it Worth It?
So is an external TPMS (tyre pressure monitoring system) worth it for your 4WD? Most definitely yes in our opinion. Yes we now have the hassle of having to remove and refit the sensors every time we air down and back up again, but in the long run we think this is a small amount of pain for a hell of a lot of gain. Again if this is an issue for you, then a TPMS setup with internal tyre sensors might be a better option for you.
But we definitely think it is worth fitting an external TMPS setup in your 4WD for these reasons:
- Constant display of individual tyre pressures and temperatures.
- Set alarms for minimum pressure, maximum pressure and maximum temperature.
- Ensure individual tyre pressures are set correctly for the driving conditions.
- Early warning signs of any potential problems.
- Solve issues while they are minor, before they become major.
- Reduced risk of major blowouts and serious tyre and rim damage.
- Increased road safety.
- Prolonged life of your tyres.
This is the exact external tyre pressure monitoring system (TPMS) setup we purchased for our 4WD. Check them out if you are interested. There are loads of options out there, so just get the right setup for your needs. If you are happy to spend a few more dollars then there are definitely better options out there. However, other than the battery problems we have had, overall our OBD2 Australia TPMS setup is not bad at all.
If you want to read more on our detailed post on how a TPMS works and why we think it is a great addition to any 4WD setup, then read our post here for more information.
If you would like to read any of our other posts on some of our gear, then check them out here. If you have any comments, questions or feedback then please comment below this post, we will respond to your questions and we do appreciate as much feedback as possible. To keep up to date on any future posts and become a part of the 4WD Adventurer community, then please subscribe to our Newsletter here. Follow us on Instagram, Facebook and YouTube to keep up to date on all our other content.
Thanks for reading this post on our 4WD external TPMS setup.
The thoughts of Peter.
10/01/2021 @ 11:07 AM
Thanks Peter, bought these also but a different brand as I tow and thought 6 would be a better option.
rideon
markcranston
05/01/2021 @ 4:19 PM
A question, when monitoring tyre pressure does the pressure change from cold to hot? (when the tyres have been run foe a while)
regards mark
05/01/2021 @ 4:29 PM
G’day Mark,
Yes they do mate. You can see pretty big changes as the tyres start to heat up depending on cold pressure, rear load and ambient temperature. If we don’t get our cold pressure right for say a bigger load in the rear, the pressure increase can be fairly large. We talk about the 4 PSI rule in this post or the other one on the TPMS. Basically if you are seeing tyre pressure increasing by more than 4 PSI then your cold pressure is too low. The same can be said if your pressures hardly moved, would mean cold pressures are too high. Having the TPMS is really interesting watching the pressure changes as you drive. I had to pump up the rears the other day as I noticed they increased by around 6 PSI, so increased them from a cold 39 to 41 PSI.
Hope that helps.
Cheers,
Peter