I did a D check on my 1991 Legacy due to some rough idiling. The fault code is 51, which is the neutral switch or the inhibitor switch. Can anyone help tell me the efects of these switches on the performance of the vehicle and the location of them?

Thanks ahead of time.

Doug

Do you have an automatic or manual transmission?

 

For AT's the inhibitor switch is on the side of the transmission.

 

For MT's, again it's on the side of the transmission.

 

If the switch is bad and the ECU doesn't know whether the car is in neutral or not, it can have some effect on idle. It'll be more noticable on AT's.