GM Service Manual Online
For 1990-2009 cars only

TFP Manual Valve Position Switch Logic

Gear Selector Position

Signal A

Signal B

Signal C

Park/Neutral

HI

LOW

HI

Reverse

LOW

LOW

HI

Drive 4

HI

LOW

LOW

Drive 3

HI

HI

LOW

Drive 2

HI

HI

HI

Drive 1

LOW

HI

HI

Invalid

LOW

HI

LOW

LOW

LOW

LOW

    • HI = Ignition voltage
    • LOW = 0 voltage