GM Service Manual Online
For 1990-2009 cars only

TFP Manual Valve Position Switch Logic

Range Signal

B

C

Park/Neutral

HI

HI

Reverse

HI

LOW

D4

LOW

HI

D3

LOW

HI

D2

LOW

HI

D1

LOW

HI

Invalid

LOW

LOW

LOW = 0 volts

HI = Ignition voltage