Home >> Land Rover >> 2021 >> Defender 90 >> Repair and Diagnosis >> General Information >> Specifications Index >> Diagnostic Trouble Code Index INGENIUM I4 2.0L Petrol - PHEV, DTC: Transmission Control Module (TCM) -- Defender/L663 >> Diagnostic Trouble Code Index - INGENIUM I4 2.0L Petrol - PHEV, DTC: Transmission Control Module (TCM) (G2815506) >> Description And Operation >> Transmission Control Module (TCM) - INGENIUM I4 2.0L Petrol - Plug-In Hybrid Electric Vehicle >> DTC P279D-86: Four Wheel Drive (4WD) Range Signal Circuit - Signal invalid >> Possible Causes