P1755 Clutch actuator fault: Incorrect position

[MarkusC2]

Hi!

Have a C2 2004 (145000km) with all software updates installed but with a Sensodrive problem...

When driving and changing gear i somtimes (without logic: 4 times a day or 1 time a week) get the snowflake-warning for the gearbox and one of the following happens:

1. When slowing down the gearbox shift down and the error resolves itself and i can continue driving.
2. When slowing down the gearbox isn't changing but declutch when i stop and then just revs. Unless i rev it to approx 3500-4000rpm when it jumps forward.
3. When slowing down the gearbox isn't changing and wont declutch so i have to brake it to a forced engine stop.

I've checked with the Lexia and there is 1 permanent error each time: P1755 "Clutch actuator fault: Incorrect position in relation to the reference value. Coherence"

Could it be the clutch actuator that's finished. Or do I get these errors due to a clutch problem. Or is it just electrical issues?

(I do get some electical temp errors that isn't showing each time
P1804 Transmission 4-Wheel Drive High Indicator Circuit Failure
P0744 Torque Converter Clutch Circuit Intermittent
P0811 Clutch overheating fault EGS Gearbox
P0750 Shift Solenoid A Malfunction
P1702 TRS Circuit Intermittent Malfunction )

Have anyone seen this before or have any ideas what to try?

Hepl needed!

[Lighty]

I changed a clutch actuator this week that had exact same fault. I wasn't sure so fitted a used one 1st, but it rectified the fault straight away. £360 + vat for a new one

[MarkusC2]

Ok, tanks!

Do you think its any idea to buy a used one or is it just to pay up for a new?
If I should by a used one, is there alot of different specs and i have to find the right one?
How hard is it to change - special tools except Lexia?

Regards, Markus

[Lighty]

I personally would fit used, I don't think there are any different models. I may be doing it all wrong, but each time I remove one, we invariably end up stripping it to get it into the "off " position. Have done it with the Lexia a few times, but they always seem to come out a bit.
Anyway Iam an expert at rebuilding them now
To fit you will need to remove battery box and air filter, which is a battle in itself. There are 3 Torx screws, undo the a little and the unit slides off.
Then you program it all up with the Lexia. This sometimes takes a few attempts , it doesn't seem to be an exact science , but I don't think it will reprogram with faults in.
Trouble is we don't do them often enough to get a good system going, often there is a month or two inbetween cars, and at my age you forget the routine.
We always use the battery charger on the car to maintain over 12.5 volts whilst programming.

[MarkusC2]

Found http://ww2.justanswer.com/uploads/nabil ... 12_cas.pdfdescription on how to change the actuator - have you done it without the pre-load adjustment?