Refilling transmission fluid on gear box Citroen C5 x7 2011

[Hide91]

Hi,

I have a Citroen C5 x7 (2011) model. (Diesel, 112HP, 1.6L, semi automatic (manual gearbox with automatic shift)

I've noticed that there's oil marks on the ground after I've been parked for a while. Removed the left front tire and noticed it was "bleeding" at the left bottom part of the gearbox. My question is. Can I refill oil here, or do I HAVE to do a full oil change? The refill is temporary till I can get to a workshop in about a month.

Considering the leakage, there's probably less oil there than the gear box needs, so refilling the exact amount is hard to do regardless of the refilling with/without a full oil change.

[GiveMeABreak]

The oil has to be replaced using a diagnostic tool like Diagbox / Lexia to first depressurise the hydraulic system for the clutch and gearbox actuators. So the oil has to be topped up to the MAX mark on the reservoir when depressurised, otherwise you can end up over-filling it. When finished repressurise the system.

[Hide91]

The oil has to be replaced using a diagnostic tool like Diagbox / Lexia to first depressurise the hydraulic system for the clutch and gearbox actuators. So the oil has to be topped up to the MAX mark on the reservoir when depressurised, otherwise you can end up over-filling it. When finished repressurise the system.

Thanks. I take it there's no way to measure how much/little oil there is right now? in terms of if its safe to drive as is for about 300km to my dads workshop(?) without killing the gearbox

[GiveMeABreak]

This is the procedure for reference:

Fluid level
The oil level is checked after depressurising the piloting actuator.

Connect the diagnostic equipment to the vehicle’s diagnostic socket.

• Switch on the ignition.
• Select from the diagnostic tool menus:
• The vehicle
• The RPO no.
• Perform the global test.

Select and validate the menus:

• Gearbox ECU
• Specific operations
• Check of the gearbox piloting actuator oil level

The diagnostic tool displays a new menu.

• Select: Depressurisation of the hydraulic circuit.
• Check the level of oil contained in the piloting actuator hydraulic reservoir.
• The oil level must be at maximum ( as "a").

Carry out:

• Top up with oil if necessary
• Pressurise and bleed the hydraulic circuit

[Hide91]

Thank you for great help. Since you use diagnostic equipment to measure when refilling oil. Does the car have a low level alarm? Like you get a warning light or a message on screen if you run low on gear oil?

[GiveMeABreak]

I would never have one of these - preferring manual or fully automatic.

I don't believe there is a warning - or none I can see referred to in the manual, so you may need to visually check the level as you go along.

[Hide91]

No, I see what you're saying. its not ideal... I'm not sure how I can visually check without the special diagnostic tool.

[Hide91]

I'm not sure if anyone still checks this one, but as it could be relevant to the issue at hand.
I was driving to the gas station and accelerating towards 90 km/t when I noticed the gears wouldn't change till 4th and so on. (stuck on 3rd) - With this it came a message like "Gearbox fault. Repair needed" in the dash. I pulled over, the service lamp went off as the speed went to 0. I managed to pull a fault code "P171A".

Can this be related? I've been reading another post on the forum here about a C3 Picasso with ET6G gearbox, but as im not sure which gearbox my cas has - I needed to ask.

[GiveMeABreak]

Pop your VIN up if you're not sure what you have. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

[Hide91]

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

Let me know if you need RPO as well

[GiveMeABreak]

No, that's OK I can get all that from the VIN.

So you have the STT 6-SPEED PILOTED MANUAL GEARBOX fitted to your C5.

The most common issue is a faulty brake switch (also listed here as one of the suspect areas):

Fault Code:	P171A
Description of Fault:	CAN and wire brake information incoherence fault: Coherence. Inconsistency between the signals on the CAN network and the wire signals. Context of appearance of the fault code: The following conditions have to be met: - Ignition on - The system is not in starting phase Technical precision on the context of appearance of the fault code: Possibility 1 Supply voltage correct between 8V and 16V (Pin 3 of the 28-way connector) Possibility 2 - No fault on the CAN network - Absence of fault codes U1000 - U1003 - U1208 Possibility 3 For a "switch stuck" fault : Engine running -Clutch closed Possibility 4 - Signals inconsistent, no other CAN or wire faults on the brake information - Absence of fault codes P0556 - P0559 - P0573
Conditions for Fault to clear:	Several brakings without inconsistency between the CAN and wire signals
Downgrade Modes whilst Fault is active:	Engine running or in Stop and Start phase - The gears above 3rd gear cannot be engaged - Activation of Manual mode Engine stopped and not in Stop and Start phase Prohibition on engaging a gear Starting possible provided the gearbox is manually in neutral with presses on the brake pedal If the vehicle has the Stop and Start system : Stop and start function deactivated
Symptoms:	Difficult/impossible to change a gear Lack of power Absence of automatic stopping of the internal combustion engine Impossible to make the vehicle move
Suspect Areas:	Gearbox ECU Sealing of the connectors and harnesses 28-way connector of the piloted manual gearbox ECU 28-way harness of the piloted manual gearbox ECU Brake switch

[Hide91]

Thank you Marc. As always, you're a lifesaver

[Hide91]

To continue on the original post and oil leakage. I managed to get a sample of sorts of the oil leaking. And the thought that strikes me is that this doesn't look like gear oil. Nor does it have that smell to it.
My thought is. Maybe this is a leakage caused by maybe a blocked Diesel Particle Filter. Could this be the case?
I also noticed theres a "gathering" of fluid in the bottom of the engine compartment when looking towards the gear box.