Home › Land Rover › 2021 › Defender 90 › Repair and Diagnosis › Quick Lookups › Common Specs & Procedures › Diagnostic Trouble Code Index DTC: Anti-Lock Brake System Control Module (Abs) -- Defender/L663 › Diagnostic Trouble Code Index - DTC: Anti-Lock Brake System Control Module (Abs) (G3134779) › Description And Operation › Anti-Lock Brake System Control Module (Abs) › DTC C0031-25: Left Front Wheel Speed Sensor - Signal shape/waveform failure › Possible Causes