C1241, C1404, C1405, C1416 where to start?

[vivalaflam]

C1416 means that your rear left speed sensor might be bad?
while C1405 is most probably the cable, and not the actual unit.
Check that connection, the plug might have some corrosion in it.
I've ordered 2 cables for the rear speed sensors because my ABS light came on with the fault codes similar to your 1405. "Open circuit on rear left/right speed sensor".

If you do this yourself, please be careful unplugging the cable from the sensor, it's a PITA to deal with. It's really fragile. Don't ask me how I know :p