Citroen C4 grand picasso 1.6 2015 semi auto P1755 gearbox fault

[Stestrange82]

Hi all I'm a new member and looking for some help and guidance
Fault code P1755
I have developed a fault which is gearbox fault repair immediately. It first did it and I had to leave the car for 5 minutes and I cam back and all would be fine again for a few days until it happened again. I read it could be the hydraulic oil in the actutator do I followed a guide where I extracted the hydraulic oil with a large syringe and replaced it and it took around 600ml of fluid but I probably only took out 200ml although no real signs of any leaks anywhere. Anyway since doing this it's still hot worse tk the point now it won't move out of neutral where as sometimes I'd put it in auto and it would skip on the screen and goto manual and allow me to drive it like that but now it won't move out of neutral.

I've put a autel on and depressurised the hydraulic actutator which it completed but with a fault I've tried to bleed and also depressurise the system now when I bleed it starts to do it then terminates action and when I try to pressurise it, it just terminates action.

Any advice on what to do and is it worth checking the auto transmission fluid. Which opens up even more questions

How do I know how much is in it and is there a way to know when it's full. Or is it better to empty and refill with new and if so how much and which type do I need.

The car itself before this fault came up run and drove absolutely fine and you would have never suspected anything was wrong with the clutch eg no slipped or judder nothing it drove absolutely fine. It's only done 64k miles

If its worst case scenario and it's going to be a clutch and DMF required how easy are these compared to a manual gearbox as I've done a few in the past is there any manuals with all the torque settings etc. Just can't seem to find much on them.

I've seen they bite point etc needs to be set etc after it's done with the diagnostics I've never done this but is it as easy as just clicking ok and it does it automatically or do you require advanced knowledge of them to set this all up?


Thanks in advance

[RichardW]

It's pretty likely it needs a new clutch. The P1755 related to the clutch position. If you can see live data you will probably find that the reported position does not match the requested position. The sensor is part of the slave cylinder - which is in the bell housing, so it's all go to come out anyway and you might as well stick a new clutch and DMF in. The actual clutch is similar to a manual one (but is not the same, you need to make sure you get the correct one). The mechanical work is the same, you need the scan tool to depressue the actuator before, then repressurise/ bleed the clutch / program the gearbox gate and the clutch biting point after.

[Stestrange82]

The programming of the biting point etc is that hard to do? Have I got to configure anything or does it do it all automatically.
I've purchased a lexia 3 diagbox but a friend has lent me a autel which has the options to depressurise and depressurise the hydraulic. I've priced up the clutch with DMF and a new thrust bear arm with the sensor on which comes in at just under £400 so not too bad. Local garage quoted £1000 for just the clutch and no dmf

[Stestrange82]

Does anyone know the transmission fluid type and amounts I require to refill after I've emptied it.

Is there anywhere I can also find the torque settings for the clutch, dMf, csc

Thanks in advance.

[Stestrange82]

I've checked the requested position and I believe it was 15.34 the position it was showing was fluctuating slighty between 15.34-15.36 would this suggest the clutch needs replacing as it felt absolutely normal and drives like normal when it does decide it will allow me to select a gear.