small grey plug hanging by accelerator pedal

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My Name: Neilcmusic1

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Posts: 50
Joined: Sun Feb 02, 2020 7:16 pm
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.6
Fuel Type: Petrol
Mileage: 80000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
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I have a petrol 2002 1.6l , I have owned it about 2 weeks , a few little niggles that ill sort , rough idle , noisy door lock (all covered on the site thank God) Air bag light on (more concerning but all in good time).

Two things I cant figure out , there is a small grey plug on a cable by the accelerator pedal , what is it for ? should it be loose?
the other thing is that in the engine bay just above and to the left of the oil filler cap is a brown plastic part which has air hoses coming out of it , its about the size of an egg , possibly a filter can anyone advise what this is ,

Thanks in advance,
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My Name: C3CAR

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Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
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Engine name: DV4 16-valve diesel (90 PS)
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Hi

There are several unused plugs on C3. Not all models have all the features.

Yours has probably just come loose.


As for the other question. Please add a photo in the correct section and ask there about the egg.

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My Name: Ozvtr

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Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
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Neilcmusic1 wrote: Sun Feb 02, 2020 10:30 pm in the engine bay just above and to the left of the oil filler cap is a brown plastic part which has air hoses coming out of it , its about the size of an egg , possibly a filter can anyone advise what this is ,
That's the purge control valve. It's purpose is to control vent gasses, that have collected in the carbon pot and top of the fuel tank, to go into the engine. It's controlled by the engine ECU and only opens when the car is "cruising".
I had one of these stick in the open position and the engine was not very happy.
My Name: Neilcmusic1

Experienced Member
Posts: 50
Joined: Sun Feb 02, 2020 7:16 pm
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.6
Fuel Type: Petrol
Mileage: 80000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
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Purge control valve ? Thats a new one on me . Thanks , it seems to be clicking but apparently that's normal so that's good thing . Never seen one of those before , I'll try and get a picture of the random plug .
My Name: Neilcmusic1

Experienced Member
Posts: 50
Joined: Sun Feb 02, 2020 7:16 pm
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.6
Fuel Type: Petrol
Mileage: 80000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
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Here's a picture of the plug , thanks
Plug found hanging down near accelerator
Plug found hanging down near accelerator
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My Name: Ozvtr

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Posts: 942
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
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The wiring looms are made in a generic fashion to fit multiple variants of cars. So it's not uncommon to find "spare" plugs in the looms. I'll have a look at my car later and see if I can get a clue, looks like it's from a loom in the kick panel?

If you look on the back of that connector you should see a lug that a clip would fit into. That lug may be broken. That plug should fit onto a plastic clip and mounted someplace, just to keep it out of the way. It has either been broken away from or just fallen off the clip. EDIT: this assumption is wrong, see my next post. The sockets mount on the clips not the plugs.

As far as the purge control valve is concerned, if you have owned a car since the late '70's you would have seen it in one form or another. Due to anti pollution laws (from then) the fuel tank vapours can not be vented directly into the atmosphere, they must be burnt by the engine. In the "old days" this was just a mechanical valve, typically operated by the engine's vacuum system , today it's an electro valve, controlled by the engine ECU. Your right, it may click on and off quickly at idle.
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My Name: Ozvtr

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Posts: 942
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
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Curiouser and curiouser - said Alice.

The wires on my plug are pink and grey but that might not mean anything as there are no wire colour codes on the wiring diagram. Only wire numbers.

I have two auto C3's. One has the wire dangling (like yours) because the loom has fallen down, as the cable clamp has detached from it's anchor point. See the picture and where it's supposed to be attached. Ignore the connector in this case as I'll get to it in a minute.
clamp.jpg
The other car has the connector plugged into a small loom attached to the clutch switch. But it's an auto and there is no clutch peddle!! The switch is just attached to the peddle box and that's it!
switch.jpg
clutch connector.jpg
The clutch switch is directly wired to the engine ECU and is only used if the ECU is in 'cruise control' mode. It drops out of cruise control if the clutch is depressed. If your car doesn't have cruise control then the clutch switch is redundant and therefore, no reason for it to be there.

If you have an auto like me, and cruise control, then the plug needs to be shorted out or the engine thinks the "clutch" is engaged. BUT neither of my cars have cruise control!!! That explains why one doesn't have the switch but not why the other one does have the switch!!!
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