42 - No. 1 speed sensor signal malfunction

The fix and cost depend on the diagnosis. The only thing the fault code tells you is the circuit or system that needs further diagnosis. There is a fifty percent chance the sensor itself is defective, in which case you would have other symptoms that you did not list. Your mechanic will perform tests to rule out wiring and connector terminal problems before spending money on a sensor. There is no set time to find a wiring problem, so it is nearly impossible to give an estimate for that. Replacement sensors vary wildly in cost depending on whether you want one from the dealer, or an aftermarket replacement from an auto parts store.

The sensors are listed as being on the transmission's output shaft housing.