I have a Citroen C4 Grand Picasso 1.6 HDi 2007 with the dreaded EGS gearbox
A couple of weeks ago I got the "Gearbox Faulty" message on the display followed by it being impossible to shift into any gear.
Selecting any gear briefly flashes the selected gear on the display (R, A1 etc) before dropping back to N
I noticed the actuator fluid was slightly below the "min" level and quite dirty, but there was no obvious signs of a leak anywhere. I checked the plastic return hose which looked fine.
None the less I drained the actuator fluid and topped up with correct type (I used SELENIA oil TUTELA CAR CS SPEED SAE 75W from shop4parts)
This didn't seem help as I was still getting the same behaviour and message on the display
I have Diagbox 7.83 which I have run and the one persistent fault code is P0868. A quick search here points to low hydraulic oil pressure.
I ran the "measurement" part in Diagbox for the hydraulic oil pressure and that does seem to start at around 55 bar and then slowly drop to 35, before shooting back to 55. This repeats and I can hear the motor spinning every 30 to 40 seconds when the pressure goes up
I’ve attached a screenshot here.
I've cleaned all the area around the actuator and electropump and there doesn't seem to be any obvious leaks and the fluid level stays pretty constant
I’ve run some of the actuator tests and sometimes I can hear the gears shifting, but most of the time I see a message “Conditions not met” before the tests appears to abort
Any suggestions or pointers for further analysis would be greatly appreciated
Thanks in advance