C4 Picasso 2010/2011 complete failure

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Zirowe
Posts: 5
Joined: 27 Nov 2020, 21:05

C4 Picasso 2010/2011 complete failure

Post by Zirowe »

Hi, I have a C4 Picasso 1.6 hdi from end of 2010 with rneg navigation system and front led status light (I belive this is the facelift version, but I'm not sure).
I have this car from the end of september, took to a mechanic and every problem with it was sorted out, so it had no prior "live" fault codes.
I have ordered from ebay a new head unit and wanted to fit in, so I started to disassembly the central console with the brake button, the two error displays and the central monitor with the two side ones.
And this is where I've messed up pretty badly: I've forgotten to disconnect the battery.
Now after I have disconnected the brake button, there was some beeping, then after the disconnection of the displays, then the AC started to boot up everytime I unlocked the car and the internal lights were flickering.
After I've recognised my mistake, I've put every component back to it's place, but to no avail: after ignition is on all 3 main displays and the two error displays are off, the brake button has no light, car beeps one long time and AC still start after every unlocking.
Tried BSI reset, same result.

I've read the fault codes with diagbox, and here they are:
U1118 Fault in communication with the BSI on the CAN
U0028 Fault in communication on the Comfort VAN network : No signal
7362 Passenger airbag deactivation switch indicator lamp fault
7363 General warning lamp fault
C994 Air conditioning compressor clutch control fault : Open circuit
P0868 Oil pressure defect
A4A7 Number plate lighting fault : Short circuit to positive
A4D4 Rear door sills or boot lighting fault : Short circuit to positive
F5FF Unexpected re-initialisation fault coming from the BSI
F020 Fault no communication with the air conditioning ECU
F023 Fault: absence of communication with the multifunction display
F029 Fault: absence of communication with the instrument panel ECU

Also no communication with a few ecus (multimedia, battery level, etc).

My problem is, that diagbox won't let me clear the faults.
I have tried clearing them with the ignition on, always faild.
I have a full chip lexia appli_xs_fuji_p106138a v4.3.0 @actia 02.01.12 and diagbox 7.855.

I think all these fault codes are from the deattached parts when I was disassembling with the attached battery, and everything actually works, just don't know how to reset to original status.
I know, I messed up.
Problem is I cant take the car to a repair shop, because the main monitors with the speed info are not alive, also I have not tried to disengage the brake.
Why is diagbox not clearing these faults and how can I solve this problem?

doctle
Posts: 948
Joined: 16 Oct 2014, 12:17
x 216

Re: C4 Picasso 2010/2011 complete failure

Post by doctle »

do this first

viewtopic.php?t=61997

User avatar
GiveMeABreak
Forum Admin Team
Posts: 22653
Joined: 15 Sep 2015, 19:38
x 2345

Re: C4 Picasso 2010/2011 complete failure

Post by GiveMeABreak »

Don't fit aftermarket head units on these cars! As you now know these are more than Audio systems, they interface with the vehicle's other systems and this is what can happen.

You simply won't be able to clear the faults if the issues still exist - which is logical. You've probably done something to the CAN wiring or there are some bad or incorrect connections and this has disrupted communication from the various ECUs to the BSI.

You need to disconnect the battery following the guide: BSI Reset / Battery Disconnect / Reconnect Procedureand then while the battery is disconnected, remove the aftermarket head unit, any wiring adapters / modifications and put the original Head Unit back in place with all the original wiring as it was.

Zirowe
Posts: 5
Joined: 27 Nov 2020, 21:05

Re: C4 Picasso 2010/2011 complete failure

Post by Zirowe »

Thank you for the answers.
Turns out I did screw up, but in a good sense: the left instrument panel was not correctly connected when a reassembled it.
Plugging it correctly back everything works again and I am only left with the "A4A7 Number plate lighting fault : Short circuit to positive", but the lights do work ok, so I dont know what might be it's problem.

As for the new head unit, its an aftermarket replacement with a proper canbus adapter and has already been installed by another c4 picasso owner.
I only screwed up by not disconnecting the batteries and not reconnecting correctly the instrument panel.
What a scare. :)

So thanks.

User avatar
GiveMeABreak
Forum Admin Team
Posts: 22653
Joined: 15 Sep 2015, 19:38
x 2345

Re: C4 Picasso 2010/2011 complete failure

Post by GiveMeABreak »

Ok, so just make sure you check everything out function wise - car options, configuration, central locking, windows, reverse parking etc., as these can start playing up. Although with this earlier C4 Pic, you probably won't have as much system integration as the later models, where you can't really use an aftermarket system.

Zirowe
Posts: 5
Joined: 27 Nov 2020, 21:05

Re: C4 Picasso 2010/2011 complete failure

Post by Zirowe »

Made yesterday a small trial run, everything seems ok for now.
And also learned that I was not able to clear previous faults, because the engine was on, but with only the ignition on, everything was fine.
Learned a lot of thins.
Btw, this is the description accordint to wich I am trying to fit the head unit, same make car, same head unit.

User avatar
GiveMeABreak
Forum Admin Team
Posts: 22653
Joined: 15 Sep 2015, 19:38
x 2345

Re: C4 Picasso 2010/2011 complete failure

Post by GiveMeABreak »

I can't open that link - it's not working on any browser.

Zirowe
Posts: 5
Joined: 27 Nov 2020, 21:05

Re: C4 Picasso 2010/2011 complete failure

Post by Zirowe »

Sorry about that, their server where down today, it's a russian page, now it's ok.

In the meantime I have another question.
I have been looking for the rneg/wipnav original headunit pinout, but the only one I have found online is this one posted by you.

On my rneg the "A" part is the same, "C" one is empty, but the "B" part has more cables/connections as the one in the picture.
Pin 1-5 and 7-11 has cables, what can they be?
I have original mic in the front and rca connector in the glovebox compartment.

User avatar
GiveMeABreak
Forum Admin Team
Posts: 22653
Joined: 15 Sep 2015, 19:38
x 2345

Re: C4 Picasso 2010/2011 complete failure

Post by GiveMeABreak »

I love the marketing on that box of the Head Unit in the second picture: "Better than expected" :rofl2: I hope so!

Connector 'C' is only when a CD changer is fitted - so that is normal.
Connection 'B' will vary depending on application / Model, but only 6 of the channels were used on the diagram I posted and they were for the microphone and auxilliary Audio inputs.

These may be different for the unit fitted in the C4 Picasso because of the different options available like rear multi media as an example.

Zirowe
Posts: 5
Joined: 27 Nov 2020, 21:05

Re: C4 Picasso 2010/2011 complete failure

Post by Zirowe »

No rear multimedia.

Can't think of any other device that should have been connected.