I have a 2021 C5 Aircross hybrid that I recently bought, I updated the system and navigation and everything was fine.
After this operation, I often received the message "Activation denied, conditions unsuitable" and the autopilot refuses to activate. Sometimes it does not activate even after turning off and restarting the engine.
All the conditions are correct, speed, type of road, visibility, etc. I also put a no name tester on the car and it found nothing on the scan.
Sometimes works great, last night it worked like a charm for 300km and today it doesn't want to work at all.
You need to get the car scanned with Diagbox or similar to see if any fault codes have been stored. Since the issue is intermittant that is the best way to know where to look
I used to be indecisive, now I'm not so sure!
I used to ride on two wheels, but now I need all four!
Yes, I have Lexia 3, but I have some 7 something version and I struggle to find some new version which knows Aircross.
Is there in this forum some links with new Lexia version?
Are you sure, "All conditions are met" there are two conditions that catches me out, slight pressure on the accelerator, and not holding the steering wheel in the right place, this is enough to stop it triggering. In fact, just completed a 120 mile motorway dash, with adaptive cruise/lane assist activated, and at about 70 mile mark, a warning message appeared "Hold onto the steering wheel", first in grey, then orange with a bong. Even though I had both hand on the wheel, they had not moved for a while, or I had just relaxed my grip a bit.
Stu
"Some cause happiness wherever they go, others whenever they go"Oscar Wilde (1854-1900)
I have a later C4 so my comments are based on that. The Citroen message is unhelpful because it doesn't tell you which conditions are not met. I get it sometimes and I am only just beginning to work out the causes. The fact that your system worked perfectly for a long trip suggests that it might be fine.
This based on the C4 'driving assist'
When you switch it on, it activates adaptive cruise control and lane keep assistance. Either could be the problem. If you turn off lane keeping assistance in the main driving aids menu (you have to do this after every engine start in later cars, don't know about 2021), when you press the button on the steering wheel it just turns on adaptive cruise control, so you might be ablle to work out which part of the system is at fault.
I can't just get in the car, start the engine and turn the system on, the parking brake has to be off as well.
When the system is on you can exceed the recommended speed. I see from your picture that you are already travelling above the speed you are attempting to set. I wonder if that causes the message? Also the display suggests that it can already see a car in front, I wonder if that might be a reason it won't switch on? Once it is on and set of course it deals with both those circumstances very well, but maybe it has to be 'clear' in order to set it. I could see that as a safety feature, you wouldn't want the car to brake suddenly when the system goes on.
I see that the speed sign is very low - I assume Kph. Is that below the parameters for switching on? I know it works well below that speed - even to a standstill - when operating but its different for activation.
There are the obvious things as well, dirt or fog on the windscreen.
It might be that your system is working fine, maybe you could try to discover the differences between when it works and when it doesn't work.
Richard_C
Current:C4 Max Hybrid, C3 1.2 Auto
Past Citroens: Dyane (x2), 2CV, Visa, BX (x2), Xantia, Xsara Picasso, C4 Picasso,C3 (x2) C5 X7 Tourer, Synergie 1.9TD, C1
Others: Hillman Hunter, Cortina Mk1, Maxi, VWT2, Granada, SAAB 900, SAAB 9-5, R5 Gordini
I have a fully automatic cruise control system. It consists of a right foot, a pair of ears, a pair of eyes and a brain. Didn't cost me a penny either!!
I used to be indecisive, now I'm not so sure!
I used to ride on two wheels, but now I need all four!
mickthemaverick wrote: 30 Sep 2025, 11:50
I have a fully automatic cruise control system. It consists of a right foot, a pair of ears, a pair of eyes and a brain. Didn't cost me a penny either!!
Same here. Mine has it fitted but only used it a couple of times just to see how (took a while to work it out). Never think of actually using it.
Strikes me that I could have used it last night, had to collect newly married son and dil from Newcastle airport at 01:00. Very little traffic. EuroCarParts lorry thundering past in a 40 zone was the most exciting part.
My first ever experience of 'cruise control' was in 1985 in my Lancia Beta Spider:
MTMO
It was fitted with a nifty hand operated throttle locking lever. You set the throttle to your chosen speed and then twisted the T handle to lock it in position. You could then rest your leg if necessary and it came off automatically if you touched the brake pedal. Perfectly adequate and no electronics needed!!
I used to be indecisive, now I'm not so sure!
I used to ride on two wheels, but now I need all four!
The first one that I encountered was on a Volvo PV444
About a 1950 model, been in a barn for at least ten years. It was a farm vehicle, covered in filth.
A mate borrowed it from the farmer for us to drive to Stockholm in to see Leonard Cohen
Was quite pleasant to drive, had spotlights on the roof operated from inside the car and a small lever near the steering wheel. The lever was quite stiff, intentionally, and linked to the throttle butterfly, so could be set at any position and maintained it.
It worked well. A long drive on very quiet, wide and mainly straight roads.
We did cleverly fill it with diesel on the way back. Car just shrugged it off but made impressive amounts of smoke.
They would allegedly run on coal dust.
When it works, it works no matter the sign on the road, the speed in that moment, if there is a car in front of me or not and so on.
I tried already with lane assist activated, deactivated.
Last edited by Mesersmith on 30 Sep 2025, 19:45, edited 1 time in total.
mickthemaverick wrote: 30 Sep 2025, 11:50
I have a fully automatic cruise control system. It consists of a right foot, a pair of ears, a pair of eyes and a brain. Didn't cost me a penny either!!
Why did you choose to pollute this topic?
I really need help, not funny things.
Sorry if that irritated you but it is hard to take things like this too seriously. Two members have already given you sensible advice and life is too short to take things too seriously when nobody's health or life is at stake!
I used to be indecisive, now I'm not so sure!
I used to ride on two wheels, but now I need all four!
Mesersmith wrote: 29 Sep 2025, 10:39I also put a no name tester on the car and it found nothing on the scan.
It's very likely that there are DTCs (error codes) there but it needs a decent diagnostic machine to read it such as a full chip Diagbox.
Mesersmith wrote: 30 Sep 2025, 06:16
Yes, I have Lexia 3, but I have some 7 something version and I struggle to find some new version which knows Aircross.
Is there in this forum some links with new Lexia version?
Is it really an old Lexia you have? You need a more modern Diagbox system for this. "7 something version" doesn't really help identify what it is.
As I get older I think a lot about the hereafter - I go into a room and then wonder what I'm here after.
Inside every old person is a young person wondering what the hell happened.
"Trying is the first step towards failure" ~ Homer J Simpson
mickthemaverick wrote: 30 Sep 2025, 14:22
Sorry if that irritated you but it is hard to take things like this too seriously. Two members have already given you sensible advice and life is too short to take things too seriously when nobody's health or life is at stake!
You're right, but I'm a little frustrated because of this matter and I really need to make it work, because I use acc in almost any situation.
So, I want to apologize my self and I'll try to be more open.
Mesersmith wrote: 29 Sep 2025, 10:39I also put a no name tester on the car and it found nothing on the scan.
It's very likely that there are DTCs (error codes) there but it needs a decent diagnostic machine to read it such as a full chip Diagbox.
Mesersmith wrote: 30 Sep 2025, 06:16
Yes, I have Lexia 3, but I have some 7 something version and I struggle to find some new version which knows Aircross.
Is there in this forum some links with new Lexia version?
Is it really an old Lexia you have? You need a more modern Diagbox system for this. "7 something version" doesn't really help identify what it is.
The hardware is Lexia 3 full chip, but the state is 7.86 and doesn't know Aircross.
For two days I try to find a newer version and I try to install 9.150, but there is always a password that is hidden and must pay I don't know what amount, or the kit it self is not working and scream for I don't know what missing file and so on.
If someone know and have a link for a newer version of diagbox, please help or advice me.
