Xsara picasso 2.0 hdi error code p0903

[Kevin Da]

Hi all,
I'm new here so please be gentle with me !!
Engine management light on ..
I've read lots of posts here and elsewhere about the error code p0903 -- clutch circuit actuator high -- but no one seems to have a definate fix for this .
My 51 plate picasso is giving the same problem ---- I let the clutch switch hang, cleared the code and it came back 2 or 3 weeks later.
Next, unplugged the switch and same thing .
Haynes manual circuit diagram shows 5 AMP in position F3 along side steering wheel with a green wire from ignition switch through a normally open clutch switch and beige wire to the Engine management control module.
I have removed F3 ,cleared the code and 3 weeks later it's come back again with a loss of power that only lasts for 10 seconds or so as long as I don't take my foot off the throttle then off we go again - normal throttle without stopping the car but light stays on.
If I notice the light come on and take my foot off the throttle I can't rev the engine as it is in limp home mode which then clears itself within a minute or so which is fine if I am on a level road but a problem when going up hill and have to use lower gears without being able to rev the engine.
The fault light will go out on it's own after a few restarts and some miles motoring with no power loss until it happens again .
I am now at a loss about what to do next ----- the thought has crossed my mind about disconnecting the battery overnight but don't want to create more problems.
Sorry for the long post but this explains it all and any help would be appreciated please.
Thanks for reading .
Kev

[Hell Razor5543]

Well, while I am not going to able to help you, I can Welcome you to the Forum, so; "Welcome to the Forum".

[Kevin Da]

That's kind of you --- thanks !!
Kev

[GiveMeABreak]

My initial thoughts are the brake switch - they are linked to the clutch switch and ECU - when the brake is pressed it signals the engine ECU to reduce fuel. If it is faulty, the symptoms you have described can occur. It happened on our C3 - had the brake switch replaced and end of stuttering and hesitation. It happened more going uphill with us too.

Post up your VIN and I'll dig the part number out for you.

[Kevin Da]

Marc.
Many thanks for that ---- When I first had the car there was a problem with the brake light switch being loose which I found when checking my lighting board and wondered why the brake lights came on when I shook the car by accident.
Maybe it's come loose again but I've not had the symptoms of the car loosing power because it thinks the brakes have been applied which is what I had before as it cuts the fuel so I've been told ---- the light didn't come on before but it's worth a check again .
Thanks
Kev
Edit : Just spotted you are in West Wales --- I'm near Haverfordwest

[GiveMeABreak]

No worries - as I said, if you post up your VIN or PM it to me I can check out the replacement part number and cost for you.

[Kevin Da]

PM sent.
Thanks for your time ..appreciated
Kev

[GiveMeABreak]

PM sent Kev, but posted here for the benefit of other members too.

Here's the diagram - Part 11 is the Brake Switch and this is Part Number 4534 52.

The price is £10.91 plus or £13.09 inc. VAT from Citroen.

Brake Pedal Toe Board Assembly

[Kevin Da]

Picked up a switch from Days ---- now the heavens have emptied !!
Unfortunately the switch doesn't come with a fixing nut -- not taking any chances with the old one -- so on order .
As soon as it's all fitted and I'm problem free or not -- which will show up or not within a few weeks --- I'll post back .
Many thanks for the help .
Kev

[GiveMeABreak]

No problems Kev - fingers crossed and brolley up!

[Kevin Da]

Hello --- this is where I 'm at .
As the error always points towards the clutch switch I bought a new one --- seemed the obvious thing to do although I would have thought that disconnecting it and removing the fuse would have removed the problem but not so.
Maybe the ECU needs to see that the clutch is pressed every now and then !!
Needed to get the car MOT'd so driving to the test centre the management light came on ---typical . Cleared it and prayed that it would not come on again for the next hour or so !!
Car flew through the MOT with the comment "it's in great condition for the age "
Today fitted the clutch switch --- make sure you get the correct one ,the lead is shorter on a left hand drive one --- and pushed the brake pedal switch in another click.
I've not fitted the new brake switch as no matter how much I thumped the old one I couldn't get the brake lights to come on when they shouldn't.
I must say that the new clutch switch is a lot tighter and has far less play than the old one.
I hope that is the end of it ------ I'll let you know .
Many thanks for suggestions and help

Kev

[GiveMeABreak]

Fingers crossed that's the end of the issue Kev.

[Kevin Da]

Engine management light back on again this morning ---- it seems to do it if I'm holding the car between 50 and 60 MPH ---- but not all the time.
I'm grasping at straws here !!
Same error cleared , back to the drawing board and more head scratching .....

Kev.

[ekjdm14]

Replaced the brake light switch yet? I ask because if it's just "flicking" every now & again it could be making/breaking contact quicker than the brake light bulbs/your eyes can react but still being picked up by the ever vigilant ECU?

Just a thought... Hope it's something simple. Also, are all the connectors to brake and clutch switches clean and tight?

[GiveMeABreak]

I would get the brake switch on as I suggested in the beginning. We had no issues with the brake lights it was the other part of the circuit that sends the signal to cut the fuel intermittently.