Circuit Description

WARNING: This page is about a different car, the 2007 GMC Yukon XL and 2007 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.

The automatic transmission fluid pressure (TFP) manual valve position switch consists of five normally open pressure switches. The transmission control module (TCM) supplies battery voltage to each range signal. By grounding one or more of these circuits through various combinations of the pressure switches, the TCM detects what manual valve position has been selected, and compares the actual voltage combination of the switches to a TFP manual valve position switch combination table stored in memory.

The TFP manual valve position switch assembly cannot distinguish between PARK and NEUTRAL because the monitored valve body pressures are identical in both cases. With the ignition ON and the engine OFF, D2 is indicated. When the transmission 20-way connector is disconnected, the ground potential for the three range signals to the TCM is removed, and with the ignition ON, D2 is indicated.

If the TCM detects an invalid state of the TFP manual valve position switch circuit by deciphering the TFP manual valve position switch inputs, then DTC P1810 sets. DTC P1810 is a type B DTC.