If you check the transmission serial number on the green plate on the LH side of the maincase, if the number is higher than 0424941 (i.e. a build date after 29th August 2001) then the transmission has the latest, upgraded, F-clutch piston. I’ve never yet seen one of these fail.

What the Sonnax article is saying is that if you disconnect the 16-pin plug at the back of the transmission you can deliberately put the transmission into failsafe mode.



Failsafe mode provides a direct hydraulic path in reverse, via the manual valve, to the C & F clutches without risking any intervention from the MV3 solenoid or the reverse gear protection valve (RG-V).



If the transmission will then reverse, you have an electrical/electronic fault rather than a hydraulic/mechanical one.

Phil