"Service TPMS" warning with valves from eBay

Let me translate that passage from Suzuki a little bit further.

Tire pressure sensor consists of a pressure sensor, acceleration sensor, temperature sensor, control section, transmitter / receiver, battery and air valve.
The "acceleration sensor" referred to is actually a spring-loaded centrifugal switch.  It is there simply to "turn on" the TPMS sensor above a certain speed.  From later in the text, we see that speed is 25kph.  It does not measure acceleration, and it is not a sensor -- this is just bad translation.

Tire pressure detected by the tire pressure sensor, along with the ID code, rolling angle position, temperature, battery status, is transmitted to TPMS control module on the radio wave.
 This seems to be a pure error.  "Rolling angle position" would require a position sensor of some kind, which does not exist -- or it would have been described in the above.  And position relative to what?  Angle relative to what?  Since we know the TPMS unit does not actually have an accelerometer (see above) it is not able to know whether the wheel is speeding up, slowing down, or in which direction it may be rotating.

So, in short, TPMS is not transmitting any kind of position, ABS does the wheel speed and travel angle analysis you describe, and Suzuki should not use machine translation for its manuals. 

Naturally, you don't have to believe me.  But ask yourself: how would a TPMS spoofing box like @DrRobin uses ever work, if the car needed to hear real-time wheel position and "rolling angle" information from each tyre?  And, what would be the point of the hardwired wheel speed (ABS) sensors?  Note that I say all this while bowing deeply at the waist and addressing you in the most formal Japanese.



@Jacket To the OP: you can ignore all this technical stuff -- we here agree that you have a duff TPMS sensor, we are just disagreeing how smart it would be if it were not duff. 

 It looks like we are going to have to differ on this

Yes, the TPMS controller picks up wheel speed information from the abs sensor. But just knowing the wheel speed doesn't mean you know which sensor is attached to that wheel.

The TPMS sensor does transmit location information in the form of data that can be used to work out the position.

It uses an acceleration sensor and you can see that in the picture, you can see the "G" reading for the sensor that has been sent by the sensor. This appears to be the method used by Suzuki particularly as one of the DTC codes is around missing or bad G reading from sensors.

As far as I am aware there are three ways of working out tyre positions.

1. Sensor in every wheel arch, this is the signal strength way. Suzuki does not have a sensor in every wheel arch.

2. Signal phase detection. The rotation of the wheel will modulate the signal with the rotation speed (version of the Doppler effect). There is no mention of this.

3. Rotation information from the sensor. The manual gives a g reading for 25km/h which points to g being used.

 

We use the same TPMS tool at work and it does get calibrated to a position on the wheel and that will follow the wheel, not sure how the Jimny system works, fitting a new TPMS we sometimes need to code that to the vehicle, not sure if that would be the same on a costumer car or not.

but if you moved the wheel from front to back, on the screen it would still read 2.1 bar lets says but it would still show in the front of the vehicle. 

I have an Iron Gates spoof box

mlines wrote:

I have an Iron Gates spoof box

How does it transmit the acceleration/angle/rotation of each individual wheel, such that the car can match it with a position?

Unfortunately you are both wrong. How it actually works is there is a small daemon in the little box bit of the valve, it has a megaphone and when the tyre goes down the daemon is squashed when it's box is at bottom of the wheel which makes it scream. The scream is then heard by a goblin in the engine bay who in turn sends a semaphore to the dashboard. If you listen very carefully to a tyre going down your can hear the daemon screaming. Honestly it's definitely this and nothing else.