Home >> Land Rover >> 2021 >> Defender 90 >> Repair and Diagnosis >> General Information >> Specifications Index >> Diagnostic Trouble Code Index DTC: Transmission Control Module (TCM) -- Defender/L663 >> Diagnostic Trouble Code Index - DTC: Transmission Control Module (TCM) (G3187879) >> Description And Operation >> Transmission Control Module (TCM) - 8HP70/45 Transmissions >> DTC P0726-21: Engine Speed Input Circuit Range/Performance - Signal amplitude < minimum >> Possible Causes