Foro Forums / C4 Picasso (B78) General Questions / ULEZ

Last weekend I have finally installed dashcam on C4P and Peugeot 107. On 107 its pretty easy, since it s very simple to hide cable. I have removed dashboard few months ago, to fix cabin fan, so it was easy to remove just one corner to hide cable. I have used hardwire method for both cars. Again, on 107 even though its a bit complicated to reach fuses, once you do, they are easy to remove. On C4P, they are like in a cave, without any light, you can work only with one hand. Grounding is possible only on one bolt which is connected to the chassis, and that one is hard to reach. Hiding cable is much more complicated, in case of C4P, I had to remove every cover on the windshield, and one around rain sensor was falling apart. Can't blame it, being in the sun for 20 years. Around dome light, and driver sunshade cover, behind door seal. Finding fuse to use, since all of them sound very important. In the end, I have used for both cars, rear wiper for ACC, and rear glass defroster on P107 for parking monitoring, and lock/unlock on C4P for the same thing. On the C4P, I had to modify a bit cover gor rain sensor, so it could be closed with cable through it.

Hi, I've had the adblu tank replaced 2 years ago and the light came in again. First states top up adblu then after a out 5 miles the countdown clock started. I topped up adblu, it took about 5 liters. On a motorway drive the countdown and warning light went off. I think the same thing happened last time with countdown turning off and back in again later. I've emailed the Citroen garage who replaced the tank last time with what appears to be a refurbished tank. But they haven't replied. Any thoughts on what to do next, possibly third party diagnosis as Citroen is very expensive. It present no faults although this wasn't with diag but with OBD.

Hi everyone, I’ve just bought a late 2016 C4 Picasso and the car appears to have Apple CarPlay. I tested it with my wife’s iPhone using a proper USB data cable and it works straight away. The problem is I have a Samsung Galaxy S25 Ultra. When I plug that into the USB port, absolutely nothing happens. I’ve tried different USB/data cables, unlocking the phone and changing the USB setting to “File transfer/Android Auto”, but I still can’t get anything to happen. Does anyone know if the later 2016 Picasso with CarPlay actually supports Android Auto, or is it one of the systems that only supports Apple CarPlay? I’m hoping there’s a way to get Android Auto working without having to change the head unit — other than the obvious solution of “buy an iPhone” 😂 Any advice on what system/software I should check on the car, or whether there’s an update/adapter that would work with the S25, would be much appreciated. Thanks!

Hi everyone. I'm hoping someone here can help with locating a part. Here's the back story. A friend in Ukraine has a broken c4, her garage need to find this part but with a 28mm diameter. I'm told by a local garage to me (who phoned Citreon) that the 28mm version is the older version of this part and not made by them anymore, It's now 30mm. Obviously, the newer version won't fit. This is my last long shot, I did search the forum but didn't find anything. Anyone heard of this before? Here's hoping. Thanks in advance Nick

Survey submitted: 28 August 2026 Your Site Name : BigRedAngus By Loeb Serial Number : 77 Colour : Sport Red Engine : 1.6i Petrol Additional Modifications from Standard :

So, this error will not erase with general OBD reader, nor Diagbox I just tried. It comes immediately when power connected. Checked Maxi fuse (OK) high speed works also (OK). Resistor controller module changed to new one (OK). Changed BSM (OK). AI said control line to ECU is broken. Really to ECU, not BSM? So it must be some of those 4 smaller pins of resistor/controller near radiator. But then where are those pins surely in ECU or BSM connector? AI says: Pin 1 (Wire 1515): Low-speed control line from the ECU (32-pin black connector, pin C4). Pin 3 (Wire 1517): Diagnostic line to the ECU (48-pin brown connector, pin M3). In my drawing: pin1 - B2 of pin3 at controller ECU. Pin3 - 28v GR connector pin 2 of BSM Vin: VF7LARFKC74113916

Hi, I bought this car an good condition at 170k kms. However obviously 20 years has passed and it's normal I guess that some things may act up, in general, with a car. Electronics / ECU: When I've run the car hot, switch off (go into the shop to buy something for example) and come back, put the ignition in position II before starting, all or some, dash lights come on (air bag, doors open etc. and this is variable and intermittent. Either they all come on, some or none. Now this obviously means that heat is affecting something like a switch? And giving the ECU a false positive. The car starts and runs absolutely fine though during this. - Could it be an earth that expands when it get hot, giving it loss of contact? The cruise control: There is an error displayed on the centre console that it is malfunctioning, when I try press the settings like + or -. - Could it be the control unit for this or just simply the switches or module on the steering? Car locks sometimes: When pressing the key to lock it, sometimes it does. This I'm convinced is the switches / sensors on the doors that have worn out and not making contact, because when I open and shut the driver's door (several times perhaps), then all of a sudden it locks - let me know The hatch most times the electric handle that unlocks it works, but other times the switch clicks without unlocking. I suspect again it's worn switch? Slight loss of power / boost: If I am overtaking or put my foot down on the motorway (it's felt whe

Hi guys I just joined the group today I am from Melbourne Australia. I have recently had the Diesel Particulate Fluid topped by my mechanics (not a Citroen dealership) and they have not been able to reset the Computer to tell the car that it has been topped up. Can some one help me please? Thanks in advance.

Hi. my newly-purchased secondhand GP has a Citroen-branded tow bar fitted, but no gooseneck and tow ball. It has a round connector with numerous sockets. The dealer has no ideas and any previous owners would be at least 500 km away and hard to track down. Citroen dealers are rare-to-nonexistent where I live (Australia). Does anyone know if one of the European brands of vertically-inserted tow balls will fit? I believe an adapter to convert to a conventional round (or perhaps even flat) 7-pin socket is available. I also note that there seems to be no provision for a safety chain attachment, which is odd. I only need to tow a small trailer. Thanks, JH.

Hi all, I have a 2010 1.6 HDI I had the error come up to say DPF fluid low So I got the pouch replaced as it was leaking but now I have a brand new one But the garage I went to could not reset the error. They have a snap-on tool for diagnostics which kept coming up with an error. They tried a generic code reader that failed. They also went to another garage down the road and they couldn't reset the error either So tomorrow I'm going to my local Citroen. They said they were only charge £50 to clear any codes but I've read other posts where even the dealer can't reset this error So my question is if they can't do it at the main dealer and once I hit 1000 mi the car will go into limp mode. Does that mean the car is written off? Or is it worth buying dial box and trying it myself? It cost about £100 all in but I don't know if anyone in the southeast area has this software and possibly help me out cuz at the moment I'm totally screwed. Thanks!

For a few years I've had the engine fault message and the Service light on. When the codes have been read, there have been pages of them, so many that clearing them and trying to see what came back resulted all coming back. My local garage just couldn't find the problems. Anyway, the faults grew to emissions problems and then the risk of the particulate filter blocking, which lead to limp mode being activated. The car would not have anything to do with regenerating the DPF, even taking it on a 120 mile drive @ 2200 RPM didn't clear it. So, I did some deep research, and it turns out that it does use Eolys fluid, which surprised me, as I had read about 10 years ago, that it didn't use it. So after 133,000 miles, it had its first top up of Eolys. It still wouldn't do a forced regeneration of the DPF, and clearing codes, only worked for a few minutes. I went and bought a cheap OBD2 reader,(£5.80 from Temu) that would clear codes and drove at 2200 rpm everywhere for a few days, cleared the codes and they have not come back. Currently, I am a happy bunny!

I recently acquired a 2014 C4 Seduction (hatch). I'm trying to locate a clean 12v power supply that I can tap into in the boot. I tried the reverse lamp and the BSI complains after a few minutes with the car running. I found an unused harness below where higher trim models have a 12v accessory socket but none of the 6 pins seem to be live. Any insights or recommendations would be appreciated.