TPMS sensors in tyres are they direct or indirect
Thread Starter
Member
Joined: Aug 2021
Posts: 109
Likes: 13
2015 SL63 AMG (R231)
TPMS sensors in tyres are they direct or indirect
I have looked but cannot find any old posts on this
My dash claimed puncher so I swapped to the tyre monitoring screen and waited for the rear offside tyre to fail far far more as it was only a tad low and I had no pullover location
Nothing happened so I resent it as normal pressures and spent the day out in the car putting it down to not topping the pressure up for a long time
Once home I topped up both rear tyres to 230kPa (32psi) and took the car for a run to find readings of of 260 and 250kPa soon rising on a fast road to 270 and 250kPa
Small note my BMW can read PSI or kPa but the SL63 only seems to read kPa can it be changed on the SL?
So somewhat swearing about the expensive accurate tyre inflator I bought 2 years ago that’s on my compressor airline I bought a new dial tyre pressure gauge to check which was correct car or inflator and today they agree to 1 psi !
So its the car TPMS wheel at fault or the system.............. are they direct or indirect? Seems Mercedes use both
If are they direct TPMS sensors........... that is the sensor within the wheel, the more accurate sensors, with a battery in them........now being 10 years old and are those batteries replaceable or is it time to change the sensor on the end of the wheel air valve?
If are they indirect TPMS sensors...........that uses the ABS sensor wheel and low car voltage
Anyone know???
My dash claimed puncher so I swapped to the tyre monitoring screen and waited for the rear offside tyre to fail far far more as it was only a tad low and I had no pullover location
Nothing happened so I resent it as normal pressures and spent the day out in the car putting it down to not topping the pressure up for a long time
Once home I topped up both rear tyres to 230kPa (32psi) and took the car for a run to find readings of of 260 and 250kPa soon rising on a fast road to 270 and 250kPa
Small note my BMW can read PSI or kPa but the SL63 only seems to read kPa can it be changed on the SL?
So somewhat swearing about the expensive accurate tyre inflator I bought 2 years ago that’s on my compressor airline I bought a new dial tyre pressure gauge to check which was correct car or inflator and today they agree to 1 psi !
So its the car TPMS wheel at fault or the system.............. are they direct or indirect? Seems Mercedes use both
If are they direct TPMS sensors........... that is the sensor within the wheel, the more accurate sensors, with a battery in them........now being 10 years old and are those batteries replaceable or is it time to change the sensor on the end of the wheel air valve?
If are they indirect TPMS sensors...........that uses the ABS sensor wheel and low car voltage
Anyone know???
Thread Starter
Member
Joined: Aug 2021
Posts: 109
Likes: 13
2015 SL63 AMG (R231)
Thank you for the reply, never ever thought about what power them
So is that a set of 4 direct from Mercedes one that properly expensive or an OME manufactured say by Bosch
https://www.autodoc.co.uk/bosch/18973635
Anyone know who made the originals and do they come preprogramed or do they need programming to the car TPMS system or wheel diameter etc.
So is that a set of 4 direct from Mercedes one that properly expensive or an OME manufactured say by Bosch
https://www.autodoc.co.uk/bosch/18973635
Anyone know who made the originals and do they come preprogramed or do they need programming to the car TPMS system or wheel diameter etc.
Thread Starter
Member
Joined: Aug 2021
Posts: 109
Likes: 13
2015 SL63 AMG (R231)
Cheers
Yes I had read that some makes do not last long. I don’t know if they are as old as the 2015 car
Seem to be working a tad better today after topping up all 4 tyres.....my compressor is one of the best things I have bought for the garage no more questionable inflator gauges in petrol stations
The plan is buy Bosch ones online and have them fitted very locally as I have X-entry.to set them afterwards
I don’t fancy deflating and moving the tyre back to bolt them on the rims myself given they are so wide with the low profile and the company that fitted this set said because of that not easy to fit
Yes I had read that some makes do not last long. I don’t know if they are as old as the 2015 car
Seem to be working a tad better today after topping up all 4 tyres.....my compressor is one of the best things I have bought for the garage no more questionable inflator gauges in petrol stations
The plan is buy Bosch ones online and have them fitted very locally as I have X-entry.to set them afterwards
I don’t fancy deflating and moving the tyre back to bolt them on the rims myself given they are so wide with the low profile and the company that fitted this set said because of that not easy to fit
