DTC P0635-44: Power steering control circuit - Data memory failure: Action

WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2015 Jaguar XKR-S, 2015 Jaguar XKR, 2015 Jaguar XK, 2014 Jaguar XKR-S, and 2014 Jaguar XKR. However, it is still accessible from the selected car via links, so may be relevant.

Refer to the appropriate electrical circuit wiring diagrams and check for intermittent faults on the power and ground connections to the instrument cluster. Repair wiring harness as required. Clear diagnostic trouble code and retest
If fault persists, check and install a new instrument cluster. Refer to the warranty policy and procedures manual, or determine if any prior approval program is in operation, prior to the installation of a new module/component