Blank infotainment and speedo

[Coypars]

2026 citroen c4 max petrol frosty morning went to car started up message on info screen system alert this infotainment system is not compatible with your vehicle.
Drove for twenty minutes no display and blank speedo nothing at all,went and done the shop came out and everything back to normal.
Surely a frosty morning shouldn't cause this a visit to the dealers upcoming i think.

[Sloppysod]

Possible cause:- it could be a software/firmware update, modern Citroëns are one the air (OTA), as you car constantly looks for an update, it could have downloaded it but not fully updated it the last time you drove you car. I have only had one black screen -"Oh hell what's going on"🫨 moment since I got my car I've two years ago.
I wouldn't worry too much unless it happens again. Then it's a diagnostic session, but taking a few photos may help prove what went on.

[Richard_C]

This is quite a long post but might be helpful. I have a C4 MHEV 2025 which as far as I know has the same 'infotainment' system although yours might have later firmware. The previous reply is correct, updates come OTA but they shouldn't self install without a prompt.

It's a good car, good value for what you get and is a comfortable way to get around. I enjoy driving it. The screen etc is a real weakness. When its all working its fine, some of the menus drive you mad and the tom tom based satnav is nowhere near as good as google maps but its "OK". But there are times when it doesn't work fine so you lose confidence, and the loss of speedometer is pretty unforgivable and can be dangerous.

I've not had the exact symptom that you did, but a few months after delivery I lost the main screen and all controls for about an hour but the speedometer stayed alive. That was on a 'day out' - fine on first part of trip, fine on next shorter bit, then on next start up nothing on main screen and little on the driver display. Much cursing, had a coffee stop, all worked on next restart.

In a little over 18 months I've had 4 occasions when the whole lot, including driver information panel, has gone blank and restarted after a couple of minutes mid journey, and losing speedometer is pretty worrying when you are in variable zones or entering 20 limits. On half a dozen seperate occasions I've got back in the car after a stop, driven off and thought 'that's odd, I'm not doing 80" or whatever only to realise that the whole system has changed into Km and Kph It's randomly decided to switch privacy mode on a few times and sometimes you get the 'spinning blue blocks' on the main screen for 20 or 30 minutes after startup. Voice assistant had been absent for months. For many months the android app reliably told me where I had parked the day before. In May I was prompted to do an update on the car which didn't change the version number but did render the mpg in the app and the 'next service' data useless and nonsense. At one point the car said it had some 1.3 billion miles and had missed its 2 year service - but it wasn't and isn't 2 years old. I did extend the connect plus service for 12 months so I am paying for this nonsense. If you have android and look on play store the myCitrien app star rating isn't too bad, but its been around in various guises for well over a decade. Sort reviews by 'most recent' and its clear that one star is generous!

Of these, losing the speedometer display on the road is the one that really matters - the others are inconvenient. You lose confidence.

Hopefully it was a one-off for you and all will be well but in case it isn't what have I done and what might you do?

First up, keep a diary of events/failures (I use a list in keep notes on the phone) and make a note of the system version on the car (settings, system, about?) and the satnav version (hamburger menu bottom right, settimgs?... it's there somewhere) so at least you can relate it all to your dealer at next service - or better, contact via the app, more later.

I wondered if the lengthy black central screen was the tom tom firmware rather than the car firmware updating itself automatically in background without prompting but there is no way of knowing.

The satnav updates its maps/data in background, that's fine because it shoudn't interfere with anything else. I wondered if the spinning blocks on startup were a result of that - every few days it checks for latest versions. So I went into 'maps' 'europe' and deleted the countries I will never drive to unplanned (Hungary, Latvia, Russian Republic, etc etc. so its checking fewer. You can always re-load them and it saves over a Gb of memory. At the same time I made sure I was connected to my home wifi so map updates would be over a fast connection. You shouldn't need to do that but if you try to manage maps without wifi it nags you. I think those 2 things made screen start up a bit quicker but again, you never really know.

There's an undocumented (or hard to find in manual?) feature that turns off the screen and music bit if you press and hold the middle of the volume/mute button. You get a clock on the screen, swipe left and right for analogue/digital. Pressing it again puts things back to normal. I've not worked out if its a proper reboot or not but it might help if things fail to run properly.

Things may be getting better. Its been almost six months since I last had the screens and speedometer disappear whilst driving. Last parked location in the app has been correct for a few weeks, the mileage in the app has been correct for 2 weeks, but 2 days ago it did its 'switch to Km' act again. I've unplugged the USB drive which had my music files from the C port and the voice assisitant now works some days (not all).

And I've reported it to "Citroen Central". Even if that car is sitting in a dealers workshop the OTA stuff has to come from Citroen so I doubt the dealer can do much. 2 reasons, one was there is no point grumbling if you don't try to get it fixed, the other is if enough people contact them something might happen. Emails got no meaningful responses so I used the contact and assistance button on the main page of the app, the "write us" button (they obviously couldn't afford 'to' in the display) and gave them loads of detail. I did get a sensible reply and it was "escalated to the technical team" who asked for more details and logs. Seems like someone is trying, or are they? I got a follow up holding email 3 days ago, after 4 weeks, so its still in the melting pot. In my contact via the app I majored on the loss of speedometer while driving - illegal and a proper safety hazard but I put all the other stuff in.

Its not just me - last month I read a long term review of the C5 Aircross in auto express, the reporter said he had lost speedometer on the M4, describing it as a minor issue but to me its a bigly-big one.

Finally, being a pessimist, I keep a car vent mobile phone holder in the door pocket. If I found myself miles from home with no speedometer I would mount the phone where I can see it. In google maps with a destination set and no connection to a car (turn bluetooth off on phone) it will display your actual speed with the map albeit in small numbers, or there are numerous GPS speed apps for android which will give you a bigger readout. (I use physics toolbox which is a great app for all sorts of things). Better than driving from Fort William to Brighton guessing your speed all the way.

Hopefully you will have no further troubles but it might be worth reporting your experience to Citroen anyway just to add weight to the bag of problems they already have. Its a good car in every other respect!

It would be interesting to know your firmware version - mine is AHW.1.30.53.10 and has been for many months. I wonder if later cars were different? It was an upgrade, maybe August 2025.