Home >> Land Rover >> 2021 >> Defender 90 S >> Repair and Diagnosis >> Quick Lookups >> Common Specs & Procedures >> Diagnostic Trouble Code Index DTC: CHASIS Control Module (CHCM) -- Defender/L663 >> Diagnostic Trouble Code Index - DTC: Chassis Control Module (CHCM) (G3139555) >> Description And Operation >> Chassis Control Module (CHCM) >> DTC C1A18-64: Pressure Increase Too Rapid When Filling Reservoir - Signal plausibility failure >> Possible Causes