how do I repair indicated by gmc p1818 ?

Question

just turned over 100,00 miles

Answer 1

P1818 Transmission fluid pressure (TFP) valve position switch indicates drive without drive ratio

The transmission fluid pressure sensor is a combine unit which consist of TCC (Torque convertor )release fluid pressure and the TFP (transmission fluid temperarature ) sensor.Worn out transmission fluid or even the wrong application transmission fluid set this code condition. At a 100,000 miles replacing the transmission fluid and filter is recommended if a transmission service has not been done.The TFP because this is a circuitry sensor does wear out over time and usage to replace the unit it is at the side of the transmission pan