As pointed out the instrument cluster should delay giving the warning (I thought 60 secs) by a given time. This is done so hard cornering won't give temporary readings that aren't necessary.
If the sending unit reading stays on for more than 45 seconds the strategy is to give the warning light. The reasoning being you aren't going to stay in a left hand corner that long. The delay circuit is in the instrument cluster.
Bosch Master, ASE Master, L1
33 years MB technician