Let us assume that the TPMS sysyem on your Citroen Relay-based Wildax Aurora is exactly the same as that used with a 2018 Peugeot Boxer.
There has been a lot of on-line discussion about owners of motorhomes based on recent Boxer chassis with TPMS wanting to lower their vehicle's tyre pressures to obtain an improved ride-quality and finding that doing this causes the TPMS to produce alarms. There has also been a lot of incorrect/misleading advice provided on-line...
The facts are as follows:
1: A Peugeot Boxer’s features do not include the capability to allow the vehicle’s owner/driver to alter the tyre-pressure data stored in the TPMS’s ‘memory’.
2: A Peugeot dealer SHOULD be able to alter a Boxer’s TPMS tyre-pressure data to values specified by the vehicle’s owner/driver. Although I’ve seen quotations or £200 or £300 stated for that task, it should take no more than a half-hour (say £50 atmost).
3: Those motorcaravanners who have had the TPMS data adjusted by a Peugeot dealer tend to be reluctant to reveal which dealer did it. (This may well be because Peugeot(UK) are clearly unprepared to authorise dealerships to make the TPMS changes as a matter of course.)
https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/TPMS-/49489/
4: It is possible for a Boxer-based motorhome’s owner with the necessary know-how, equipment and software to adjust the TPMS data to his/her requirements, but I am only aware of one (very competent) person who has done this.
5: The Boxer TPMS has no ‘self learning’ capablity that would permit the tyre pressures to be reduced and the TPMS to recognise, tolerate and store the lowered pressures. No ‘direct' TPMS system has that capability.
6: If a Boxer’s TPMS is triggered by a tyre’s pressure falling below the TPMS’s low-pressure threshold and that tyre is then reinflated to a pressure above that threshold, the TPMS SHOULD recognise that this has happened and the warning should cease to be given. However, it should not be expected that the TPMS warning will stop immediately. I don’t know what the Citroen/Peugeot handbook says about this, but the handbook for the Fiat Ducato (that almost certainly has the same TPMS) states
"The tyre pressure monitoring system (TPMS) warns the driver of low tyre pressure on the basis of the cold inflation pressure prescribed for the vehicle....
The TPMS continues to advise the driver of the low tyre pressure condition until this is corrected; the warning continues until the pressure corresponds or exceeds the pressure prescribed for the cold tyres. When the low tyre pressure check warning light turns on continuously, the inflation pressure must be adjusted until it reaches the pressure prescribed for cold tyres. After the automatic update of the system, the tyre pressure control warning light switches off. You may need to drive the vehicle for about 20 minutes at a speed higher than 20 km/h to allow the TPMS to receive this information."