I would think "there is no code for male motorist needs assistance" might be better read "this list has no such code". I have seen a number of these lists of 10 codes. They are of varying length and content. Unless there is an ISO type organization with a formal standard for the codes the sexism may well be in the list generator, not necessarily the code.
While todays society has little room or need for sexism, under other circumstances it makes lots of sense. Think of two populations. One has 99% of its females killed, the other 99% of its males. Which will recover from the disaster more quickly? There are other less extreme examples.