My first choice for M2 D4L heater would be an Eberspacher Easystart PRO which has great diagnostics plus timer and temp regulation functionality with built in temperature sensor option included.
Your Eberspacher 801 controller unfotunately is NOT compatible with M2 D4L Eberspacher heater. You are correct in thinking that an Eberspacher 802 controller would work, but to be honest an 802 controller would definitely not be my first choice. It's functionality is very limited on the M2 D4L ( it does not have, error fault code reading function, so no diagnostics for future-proof operation).
My second choice Eberspacher Easystart Select which provides simple operation, diagnostics but less comprehensive, with no internal temperature sensor.
Thanks for getting in touch, any questions just email sales@butlertechnik.com
David
