C4 Picasso under bonnet fusebox

[RichardW]

Anyone changed one....

Been getting sporadic ESP / handbrake fault coming up - changed the brake light switch a couple of weeks ago which improved things a lot, but it's still there. Finally got a Lexia and plugged it in, expecting to see Yaw sensor or steering angle sensor - but no, only fault is U1208 - communication with engine ECU. Google suggests this is probably caused by a failure of the underbonnet fuse box (although failed wiring at the back of the battery is also possible). It's not a disaster (£150 on the bay new - not coded AFAIK so could go 2nd hand but then risk the replacement being no better!), but no idea what it's like to change. We had the one out of my mate's C5 when we did the clutch and wrecked it putting it back in

I couldn't easily see how to clear the faults in that ECU, but then it was raining, and a 2 year old was clambering all over me

Slightly more worrying is a slew of EGR valve faults in the engine ECU.....

See my thoughts about chopping it in when the oil strainer blocked up.....they're returning

[wheeler]

The wire that rots behind the battery normally causes a complete non start situation & no communication with the ABS ECU but it could be worth checking first.
The C4 Pic fusebox should be almost identical to the C5, How did you manage to break it & why did you have it out for a clutch change ?

[Mandrake]

Been getting sporadic ESP / handbrake fault coming up - changed the brake light switch a couple of weeks ago which improved things a lot, but it's still there. Finally got a Lexia and plugged it in, expecting to see Yaw sensor or steering angle sensor - but no, only fault is U1208 - communication with engine ECU.

You might have been too slow getting the Lexia onto the car - some temporary faults are automatically erased quite soon after they stop misbehaving so I'm not surprised nothing was listed. If it happens again get the Lexia on it ASAP and I think you'll find something.

Google suggests this is probably caused by a failure of the underbonnet fuse box (although failed wiring at the back of the battery is also possible). It's not a disaster (£150 on the bay new - not coded AFAIK so could go 2nd hand but then risk the replacement being no better!), but no idea what it's like to change. We had the one out of my mate's C5 when we did the clutch and wrecked it putting it back in

Not sure how communication failure between the two ECU's would be caused by problems in the fuse box - I would have thought that would cause one or the other ECU to fail to work at all, and the symptoms of that would be more obvious than a warning on the dash. If it was my car I'd be trying to find the connectors for the two ECU's in question and giving them a good clean with contact cleaner and also do a visual inspection of the wiring harness between them. (Easier said than done I know!)

[RichardW]

The wire that rots behind the battery normally causes a complete non start situation & no communication with the ABS ECU but it could be worth checking first.
The C4 Pic fusebox should be almost identical to the C5, How did you manage to break it & why did you have it out for a clutch change ?

Does the wire drop right off wheeler, or just go a bit thin looking?

Re the C5 - took it out 'coz Haynes said so IIRC it was obstructing the gearbox mount in any case - perhaps it is possible to get the box out without removing it with practice - but it was hard enough as it was. Break it? Easy - there was an ominous crack as my mate tightened up the nut on the main power post. Must have broken the supply off the board. It started intially, but then refused to later on with all sorts of random-ness going on....

You might have been too slow getting the Lexia onto the car - some temporary faults are automatically erased quite soon after they stop misbehaving so I'm not surprised nothing was listed. If it happens again get the Lexia on it ASAP and I think you'll find something.

Maybe, sure the light was on earlier in the day, so it would have had 2 start max since.

Not sure how communication failure between the two ECU's would be caused by problems in the fuse box - I would have thought that would cause one or the other ECU to fail to work at all, and the symptoms of that would be more obvious than a warning on the dash. If it was my car I'd be trying to find the connectors for the two ECU's in question and giving them a good clean with contact cleaner and also do a visual inspection of the wiring harness between them. (Easier said than done I know!)

Dunno - might be one of those things where replacing the fuse box fixes it, but in reality the act of unplugging the connectors etc is enough to fix it. That was going to be my first job anyway, drop the battery out, have a look at the wires behind, and then the connectors and fuses on the board.

[citronut]

Richard i spoz this isnt the fuse box you require

http://tinyurl.com/p6h7fvl" onclick="window.open(this.href);return false;

[Lighty]

Worth checking with Citroen, most of the C4 Picasso fuse boxes are £50 + vat

[RichardW]

Malcolm - don't think so, believe that is the BSI unit. Price is very good for what it is though - Citroen want £360!!!

Lighty - part number for mine appears to be about £170 - unless I am looking at the wrong fuse board....(believe it's one like this) that's the part under the plastic cover at the rear NS of the engine bay next to the battery. Only too pleased if it's another one somewhere which is cheaper... but if you can get the same for £50, then I'd be happy to pay a handling fee on top!

[citronut]

ok Richard,

the one in your link is from a salvage yard though, is that such a good idea on this type of part??????

[RichardW]

Just an example Malc, first one that came up on a search - I would certainly only fit new. The part number (which I can't remember off hand) turned up a hit on a genuine one for a bit less than Citroen. There's a possibility that the 307 has the same board, so I might be able to do a swap to confirm diagnosis - in fact the 307 may not be that bothered as it doesn't have ESP.....

[RichardW]

@ lighty, interesting info from service.citroen:

Part Number Description Quantity Price excl. VAT Price incl. VAT Total incl. VAT Selection
00006500FG FUSE BOX 141.61 GBP 169.93 GBP 169.93 GBP

9675877980 FUSE BOX 52.94 GBP 63.53 GBP 63.53 GBP

Ours gives 6500FG - change to the 96 number occurred at RP 11438 - ours is just before that (11382 IIRC). Wonder what the difference is, and if the newer (and substantially cheaper!) one will fit???? Comparing photos from e-bay (where you can buy the cheaper one for MORE than Citroen if you want ) the connectors are the same, but there are some differences in fuses, and componenents visible through the top of the board, suggesting it would plug in, but may well not play. Unless anyone wants to lend me one to try out

[citronut]

that first part No. comes back as no document found on pug service box,

the second comes back with

1 document(s) found for 3008
1 document(s) found for RCZ
1 document(s) found for 5008
1 document(s) found for 407

[wheeler]

The wire that rots behind the battery normally causes a complete non start situation & no communication with the ABS ECU but it could be worth checking first.
The C4 Pic fusebox should be almost identical to the C5, How did you manage to break it & why did you have it out for a clutch change ?

Does the wire drop right off wheeler, or just go a bit thin looking?

Its a thin blue wire that rot's, it can look like its in one piece but if you give it a tug it breaks apart. if you look at the fusebox on the battery positive terminal there is a blue wire coming off one of the mini fuses, its that wire. follow it down the back of the battery.

[Lighty]

@ lighty, interesting info from service.citroen:

Part Number Description Quantity Price excl. VAT Price incl. VAT Total incl. VAT Selection
00006500FG FUSE BOX 141.61 GBP 169.93 GBP 169.93 GBP

9675877980 FUSE BOX 52.94 GBP 63.53 GBP 63.53 GBP

Ours gives 6500FG - change to the 96 number occurred at RP 11438 - ours is just before that (11382 IIRC). Wonder what the difference is, and if the newer (and substantially cheaper!) one will fit???? Comparing photos from e-bay (where you can buy the cheaper one for MORE than Citroen if you want ) the connectors are the same, but there are some differences in fuses, and componenents visible through the top of the board, suggesting it would plug in, but may well not play. Unless anyone wants to lend me one to try out

I have a £50 one at work, with the part no, will take a pic of it tomorrow & post it up, could send it you for a trial if you like.

[RichardW]

Cheers Lighty - some pics would be useful. If it's dry at the weekend I might try and get a look at it.

[Lighty]

Here you go