GM Service Manual Online
For 1990-2009 cars only

Transmission Range Switch Logic

Gear Selector Position

Signal P

Signal A

Signal B

Signal C

Park (P)

On

On

Off

Off

Reverse (R)

Off

On

On

Off

Neutral (N)

On

Off

On

Off

Drive (D)

Off

Off

On

On

Intermediate (I)

On

On

On

On

Low (L)

Off

On

Off

On

On = Ignition voltage

Off = 0 volts