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 (P or N)

HI

LOW

HI

Reverse (R)

LOW

LOW

HI

Drive 4 (D)

HI

LOW

LOW

Drive 3 (3)

HI

HI

LOW

Drive 2 (2)

HI

HI

HI

Drive 1 (1)

LOW

HI

HI

Invalid

LOW

HI

LOW

LOW

LOW

LOW

    • HI = Ignition voltage
    • LOW = 0 voltage