Summer is coming and it is time to change tires. I am way too lazy to change tires by myself, so I decided to outsource this activity. Only thing I need to do is carry tires to the car, drive to the service and wait car back.
I did ask a quote from few places and for my surprise they actually responded to my query. Previous experiences has been that not that many companies responds to emails, even they advertise email addresses. This applies specially to the automobile industry.
I did choose the closest service to my location. First I though that I just drive there but quickly found out that I need to reserve time. This is because they want to limit number of customers waiting at the lobby. Might be a wise move for the time being!
All went fine. I was lurking what the service guy is doing and noticed that he is inside my car figuring out the e-Boxer buttons and switches. I realized that most likely he is not testing how the Harman/Kardon sound system works. He is wondering how to reset TPMS system.
When I paid the service and received car keys back, I asked that did he reset it. Answer was just like I suspected. He tried to figure out how to do it but couldn’t find any related menu for that. But according to him no warning lights was issued.
Tire Pressure Monitoring System (TPMS) error
On the way home orange warning light was lit. Maybe I should change my profession foreteller. I kind of expected that, if nothing was done at the service.
Next step was to consult user manual what it says about tire change and resetting TPMS. For my surprise 2020 e-Boxer Forester should automatically detect tire change and no resetting needed!
You need to drive 10km over 40km/h speed and light should disappear. Service is just about 10 km away from my home and it is stop and go traffic. So I though that maybe I need to drive a longer distance. That I will do on next day.
Driving a longer distance to reset TPMS warning
I decided to drive towards nearest Subaru service and see if the light goes off. After driving a good amount of kilometers, speed varied from 80 to 100 km/h and finally arrived to the yard of Subaru service. Light did not go off. I even restarted the car, but orange warning stayed there.
Again, I kind of knew it would not go off. So it was a good decision to drive towards the service. At least now I can ask for some help.
Below is a shortened version of the discussion. It appears to be a very Finnish style conversation. Very direct and straight to the point.
Did you came to pickup your car – asked the service manager
No I did not – I replied
What is your business then?
I told that tires was changed recently and now TPMS warning does not go away.
What car it is? – asked service manager
Forester e-Boxer – I replied
Oh, e-Boxer. I will go and check with the service guy
After a while he came back and continued…
Have you bought it from us?
No, I have not
You should then consult with your own dealer, maybe they have messed something – he suggested
Car is bought 600 km away and therefor not able to go there because of this – I told them
Discussion continued with same instructions as user manual says and then me advising them that I have already drove more than 10 km and faster than 40km/h and light still doesn’t go away.
As seen from the discussion above it was somewhat difficult to get help but I finally managed to service time scheduled.
TPMS sensor ranges
Right tyre pressure can be checked from the badge located in B pillar. Valuable information what I received from the discussion with service is that TPMS range needs to be set right. There is a dedicated button hidden in the glove department to set that. See also manual section 7-33 for more details.
- TPMS1 is for normal load
- TPMS 2 is for loaded car, i.e. many passengers and lot’s of cargo in car
- TPMS 3 is meant for towing. Note it is not allowed to tow Forester itself but when you are e.g. towing for a trailer.
To use secret button in the glove department press “set” button for more than 3 three seconds. Then you can cycle through TPMS 1-2-3 settings. Once you have selected correct one, press “set” button again for more than three seconds and that one is now selected.
So I managed to get service time scheduled. This time service was first class service and I was very happy about it. Everything went as agreed, even more than I was expecting. Service started when it was about to start and I was able to wait them to fix the car. Time went very quickly while doing some work via the remote connections.
Service manager came and said that car is ready now. Problem was that sensors was not activated at all. This was something that was required to be done during initial service before car was handed over to me. Great news was that I was not invoiced at all for this job. As there was nothing broken, they could invoice me. I bought car from dealer “A” and maintenance was carried out in dealer “B” due to the distance to “A”. Therefor they could invoice me as this is not matter of guarantee. But all went fine and TPMS is working again.
Why would you need a TPMS system?
As you can see from the picture above it is a very convenient way to monitor tyre pressures directly from the dash. Sure you can go to fuel station and check pressures there but I like the easiness here. Specially if weather gets colder and outside temperature drops significantly, it is recommend to monitor pressure.
I general there is following thumb rule. When outside temperature drops by 10C degrees, tire pressure drops by 0.1 bar.
Subaru recommends that in normal conditions front tire pressure should be 2.3 bar and in rear 2.2 bar. So if you check readings from cold tires and outside temperature is at that given moment +10C and next day temperature goes to -10C. That is already 20 degrees difference and tire pressure has dropped 0.2 bars.
Multifunction display presents tire pressures in kPa (kilopascals) format but that is very easy to convert bars and vice versa. 2.3 bars is 230 kPa and 2.2 bars is 220 kPa.
I prefer to keep slightly over pressure (= 0.1 – 0.2 bars) in my car compared to the manufacturers recommendations. That helps in fuel economy and then also it is not that prone for colder days. Underpressure affects to both fuel consumption and handling in negative way.
Can I drive with my TPMS light on
If you are sure that system is working as expected, then it is not adviceable to continue driving (i.e. light is not lit due to the tire change). Stop your car and see if there are any visual damage. Forester owners are lucky, since you can see the actual readings right from the dash and determine which tire is originating warning.
It is also adviceable to consult your local Subaru road assistance for further help.
Appendix: Wiki article of TPMS systems