A voltage detection circuit utilizes a comparator to compare first and second input voltages to generate a control signal when the difference between the first and second input voltages exceeds a threshold. The wheel position detecting device judges whether reception strength data is correct or incorrect based on whether reception strength indicated by the reception strength data transmitted back to the vehicle-mounted receiver from each wheel-mounted transceiver is within a range set in advance. The process may desirably include curing at atmospheric pressures to reduce the expense and equipment required in carrying out the process. Tag bit may indicate communication interface or IO driver type.