I dont have TPMS on my van but came across this. Whether its relevent to Boxer, relays i dont know.
TPMS WARNING LAMP LIGHTS UP, ERROR CODE C1010,C1012, C1014, C1015If the TPMS warning lamp lights up on the above-mentioned vehicle and the error code C1010/C1012/C1014/C1015 (TPMS system) is stored in the control unit, a software update can provide a remedy.However, all components, fuses and the power supply that could also be the cause should first bechecked.A software update can be carried out, for example, using Hella Gutmann macsRemote Services or bymeans of a pass-through-compatible diagnostic device taken from the mega macs series. Furthermore,registered access to the vehicle manufacturer's online portal is required. If the appropriate equipment isnot available, please contact an authorised specialist workshop.
TPMS WARNING LAMP LIGHTS UP, ERROR CODE C1010,C1012, C1014, C1015If the TPMS warning lamp lights up on the above-mentioned vehicle and the error code C1010/C1012/C1014/C1015 (TPMS system) is stored in the control unit, a software update can provide a remedy.However, all components, fuses and the power supply that could also be the cause should first bechecked.A software update can be carried out, for example, using Hella Gutmann macsRemote Services or bymeans of a pass-through-compatible diagnostic device taken from the mega macs series. Furthermore,registered access to the vehicle manufacturer's online portal is required. If the appropriate equipment isnot available, please contact an authorised specialist workshop.