Home >> Jaguar >> 2019 >> XF S >> Repair and Diagnosis (Single Page) >> Quick Lookups >> Common Specs & Procedures >> General Information - Diagnostic Trouble Code (DTC) Index (IGENIUM 2.0L Diesel Pcm P0401- P22FE-85) -- XF/(X260) >> General Information >> Description And Operation >> Diagnostic Trouble Code Index - INGENIUM I4 2.0L Diesel, DTC: Powertrain Control Module P0401-00 To P06D1-9A (G2142189) >> DTC P0634 - 85: Control Module Internal Temperature "A" Too High - Signal above allowable range >> Possible Causes