Here's a challenge for you! C4 GP 2006 - Pictures in links

[entotre]

Hi, there is a connector that I cannot for the life of me unplug in my Citroen Grand C4 Picasso 2006.

Can anybody tell me how I can get it out? Do I have to push a plastic part? See this link for what connector I am talking about, it is just under the oil filter cup above a pipe of some sort going into the block. Here are two pictures of the connector I am talking about.

Overview, connector in white circle:

Location in engine

Close up:

Location of connector under oil filter

The reason I want to get it out is because there have been spilled oil all around it and I have a "Gearbox faulty" error showing randomly. And based on this video it makes sense to clean this plug:

Oh, and by the way, does anybody know what this plug does/ goes into? Any guidance on this is highly appreciated!

I also need to take off the two connectors going into the gearbox ECU.... again, how do I get these off without breaking anything?

[wurlycorner]

Should be that you press either the front or rear of the clip you can see in the middle/top of the plug and pull it!

[entotre]

wurlycorner, thank you for your reply.

I will have another go later today with a screwdriver and see if I can get it out. Please see the attached illustration to see the connectors I need to get off. On the ECU multiplugs, is it an arm that needs to be flipped over to get it off?

[entotre]

Update:

• Cleaned the three connectors last night. They were full of both grease and corrosion.
• Did a test drive and to my disappointment it still had issues dropping in and out of automatic gear mode.
• Noticed a pattern while driving that it went back to automatic mode when I pressed the brake pedal.
• I had previously changed the brakelight switch because someone indicated that a broken brake light switch can cause issues for the ECU. But at the time this did not make a difference.
• I went back to the brake light switch. Removed it from the switch holder and let it just hang in the wire by the pedals. I testdrove the car(with the brake lights on permanently because of the switch) and the car drove fine through all gears.
• I disconnected the switch, cleaned up the connectors, adjusted the length of the switch “arm” and plugged it back in.
• Hey presto, it all works with brake lights and everything!

…So the short story is that the brake light switch gave me the “Gearbox faulty” warning and all sorts of other funky behavior.

[wurlycorner]

Great news that it's sorted for 'free'

[zundapp]

Hi entotre - I have the same 'Faulty Gearbox' issue as you and had already taken all the steps you have. I replaced the brake switch, but didn't adjust the new one in any way, and the fault is just as before
How did you adjust your brake switch?

Cheers, Tom