LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 2007 >> Lucerne CX >> Repair and Diagnosis >> External Pages >> Different car >> Section 246 (Automatic Transaxle - 4T65-E - Overhaul) >> Description and Operation >> Automatic Transmission Hydraulic Diagrams >> Park or Neutral - Engine Running (Park - With Touch Activated Power) >> Transmission Fluid Pressure (TFP) Manual Valve Position Switch Assembly (34)

Transmission Fluid Pressure (TFP) Manual Valve Position Switch Assembly (34)

WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2006 Saturn Relay, 2006 Pontiac Montana SV6, 2006 Pontiac Grand Prix, 2006 Pontiac G6, and 2006 Chevrolet Uplander. However, it is still accessible from the selected car via links, so may be relevant.

The automatic transmission fluid pressure (TFP) switch is attached to the valve body and consists of one fluid pressure switch that monitors TCC release pressure. This switch is used as a diagnostic tool to confirm that the TCC is actually off when it has been commanded off by the PCM.

The TCC release switch is a normally closed pressure switch. A normally closed switch allows current to flow from the positive contact through the switch to ground when no fluid is present. Fluid pressure moves the diaphragm to disconnect the positive and ground contacts, opening the switch and stopping current flow. This change in switch state electronically signals the PCM that the TCC is released.