Inhibitor Switch
When the driver shifts the gear stick, an inhibitor switch transmits data on the position of the interior gear stick to the transmission. The data signals to the TCM where the gear is positioned; Park (P-range), Reverse (R-range), Neutral (N-Range) and Drive (D-range). When the gear is in the P and N range, the start relay receives an output signal and the gear's position of the R range turns the reverse lamp on.