C4 Grand Picasso gearbox fault

[Nizace]

Hi,
I came across this site while searching a P1218 code that the snap on tool came up with on transmission.
My issue is a gearbox fault that appears to be intermittent. My suspicion is the clutch is going.
When attempting to put the gear lever into Auto or semi auto it pauses then pops up gearbox fault, effectively refusing to select the forward gears. It always selects reverse without issue.
The fault can also appear while driving. This can happen when slowing down or while at a constant speed without changing gears.
The fault appeared after going to a garage for my MOT repairs ( front droplink and bush and a possible dry crank sensor).
A garage has tried to adjust the clutch actuator and gear selector actuator without success.
My local citroen specialist is adamant that it is the clutch going and may cost in excess of 1500 plus vat. I may also have to replace the double mass flywheel.
Does anyone have any other ideas on the cause or where to look before I replace the clutch?

[GiveMeABreak]

Do you have your VIN, as I'm not getting a valid fault code for P1218 - so can you also confirm the code number is correct? Are you sure it is not P1208?

[Nizace]

Yeh Im sure it was 1218. The other code was a u1208. I found this forum by searching for P1218. It generally related to gear selector signal incoherence.

[GiveMeABreak]

Yes, but codes are vehicle and system specific. So without your VIN I can't match it up or confirm if it is relevant to your specific vehicle.

Your VIN is automasked on post submission, so just type it up as only staff can see it.

[Nizace]

Vin is VF7**************[VIN obfuscated, can be read by forum staff]

[GiveMeABreak]

As I mentioned earlier, this fault code is not being returned for this vehicle. That can be a problem with non-OEM diagnostics as they can't always read the full constructor codes. I've checked all the possible engine fault codes and also the piloted gearbox codes and it is not listed against this vehicle (DV6TED4) 110.

[RichardW]

It's probably P1718....

[Nizace]

It's probably P1718....

Yeh thats also likely.
Ill have to borrow my mates snap on tool again and check again. The error has come and gone 6 times in the last hour. It goes when it doesn't detect it. Id expect a clutch slipping issue to be permanently on.

[RichardW]

You need to get into the live data to see what it is saying about the gear selection vs the required selection, operating pressures, clutch engagement etc. Have you checked around the actuator on the front of the box that it hasn't lost oil?

[Nizace]

I asked the garage to look into it and they said they'd adjusted the actuator but not much else. Only charged me 40 so prob didnt do anything.
There is oil leaking from one area but ill have to attach a picture of it later when im back at the car. I dont believe its over the gearbox but it could be interfering with other areas.

[Nizace]

So as I'd mentioned, this is where i see the oil leak coming from. Not sure where its from or what its causing but could be an issue either way

[RichardW]

That's the turbo - if you look to the right of there past the radiator top hose you will see the actuator on the front of the gearbox.

[Nizace]

That might explain the slow uptake feeling like its in limp mode.

[myrfos]

I've been having a problem with my semi-automatic 2007 C4 Picasso Grand for the past year.

Initially, a 'Gearbox Faulty' signal came up on the dash and it would then go into Neutral and lose power randomly. Even trying to change it to Manual mode didn't work.
After a minute or so, it would restart and I would finish my short journeys, but still a nightmare on busy roads.

This happened every 3-4 months. And each time I would take it to the garage, they topped up with automatic transmission fluid and the problem seemed to be solved. So it, evidently, had a bad leak. Then it started happening more frequently as the leak got worse and when it needed re-filling every month or so, I took it to the garage again. The diagnostics check even found the fluid to be the problem.

It got as bad as needing to be topped up every week. When the fluid level got too low, it would lose power again. I was advised to look for another gearbox for it, but appreciate that both mechanics I spoke with wasn't too familiar with these parts.

In the meantime, I tried two stop leak fluids. A can of 'Wynne's' which seemed to halt the leak for 3 weeks before it needed topping up.
Then I tried Lucas stop leak transmission fluid which seemed to stop the leak completely - and it worked perfectly for a month.

But even with plenty of red transmission fluid remaining, the GEARBOX FAULTY reappeared. It's as if the solution was too thick to lubricate the gearbox..

I'm just wondering if the gearbox can become 'faulty' as described and still work well for periods, or is there a simple solution I and the mechanics are overlooking? Any suggestion would be great.

Thanks.

[GiveMeABreak]

If you are talking about the special oil for the hydraulic Gearbox and Clutch Actuators, then I think you've totally put the wrong oil in. It uses a special oil for the Piloted Manual Gearbox (https://www.porza.co.uk/product/gear-oi ... ot-9979.a4). Anything else can lead to the destruction of the system. Using anything else like sealers is sure to cause additional problems to the hydraulic system.

You need to have the vehicle diagnosed properly with Lexia / Diagbox to find out the fault codes, but I think you may have added to the problem now with all the incorrect oil and other stuff that has been added. I either case, and again talking about the actuator system, this oil level has to be checked and filled with the hydraulic system is depressurised. If you have been filling it up when the system is pressurised, then you have likely been over-filling it....