For 1990-2009 cars

Gear Selector Position | Signal A | Signal B | Signal C | Signal P
--- | --- | --- | --- | ---
Park | LOW | HI | HI | LOW
Park/Reverse | LOW | LOW | HI | LOW
Reverse | LOW | LOW | HI | HI
Reverse/Neutral | HI | LOW | HI | HI
Neutral | HI | LOW | HI | LOW
Neutral/Drive 6 | HI | LOW | LOW | LOW
Drive 6 | HI | LOW | LOW | HI
Drive 6/Drive 4 | LOW | LOW | LOW | HI
Drive 4 | LOW | LOW | LOW | LOW
Drive 4/Drive 3 | LOW | HI | LOW | LOW
Drive 3 | LOW | HI | LOW | HI
Drive 3/Drive 2 | HI | HI | LOW | HI
Drive 2 | HI | HI | LOW | LOW
Open | HI | HI | HI | HI
Invalid | HI | HI | HI | LOW
Invalid | LOW | HI | HI | HI
HI = Ignition voltage LOW = 0 volts