Citroen C4 -2022 fuse diagram/parking assist issue SOLVED

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

Moderator: RichardW

Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Citroen C4 -2022 fuse diagram/parking assist issue SOLVED

Post by Fredrikrosen »

Hello all.

I recently mounted a towing bar to my C4 155 puretech -2022 including the electrical that is needed. To get + for the small canbus box that is included did i take it from a small cable in the rear that was connected to the parking assist ecu located in the rear. It first was ok, but after first use with a trailer do i now get parking assist failure. I have removed the cable i used for getting + but no difference. Can it be a fuse or is it the ecu that might have failed? Any tips? :(
Last edited by Fredrikrosen on 27 May 2024, 20:07, edited 1 time in total.
Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by Fredrikrosen »

After connecting a Foxwell scanner does it say ”connection/communacation fault parking ecu”. So maybe i need to try another parking ecu?
User avatar
GiveMeABreak
Forum Admin Team
Posts: 38098
Joined: 15 Sep 2015, 19:38
x 5915

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by GiveMeABreak »

You can't just connect these things up to the CAN network or you'll very likely end up with problems if. You should never splice into the CAN network wiring as it can interfere with the data signals being sent and may affect ay of the ECUs on the network.

To be honest, I would recommend you only purchase an officially approved electrical kit designed to work with the various electrical architecture of the vehicle. It may cost more, but it will be approved to work and interface correctly and allow the car's ESP system to employ special programmes when towing, as well as disable the parking assistance feature as required.
Please Don't PM Me For Technical Help

Marc
Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by Fredrikrosen »

GiveMeABreak wrote: 22 May 2024, 10:11 You can't just connect these things up to the CAN network or you'll very likely end up with problems if. You should never splice into the CAN network wiring as it can interfere with the data signals being sent and may affect ay of the ECUs on the network.

To be honest, I would recommend you only purchase an officially approved electrical kit designed to work with the various electrical architecture of the vehicle. It may cost more, but it will be approved to work and interface correctly and allow the car's ESP system to employ special programmes when towing, as well as disable the parking assistance feature as required.
I totally agree, the thing is it do not help i try another parking ecu. Same problem.

The controll unit for the trailer is connected to a 12volt cigarett socket in the front, so this is not the issue anymore. Can there be a fault code that only Lexia can remove?
Any advice? :(
User avatar
GiveMeABreak
Forum Admin Team
Posts: 38098
Joined: 15 Sep 2015, 19:38
x 5915

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by GiveMeABreak »

No, lexia cannot remove fault codes if the fault is still there. Sounds like a bit of a mess to be honest and I can't really advise on what the issue is being that the CAN enabled ECUs are on a data network with the master / controlling ECUs being the BSI and the engine ECU depending on the network. So it's possible the after-market equipment was not CAN compatible with your vehicle and may have caused some problems further up the line. Have you removed the whole thing and made good any splicing?
Please Don't PM Me For Technical Help

Marc
Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by Fredrikrosen »

GiveMeABreak wrote: 22 May 2024, 14:59 No, lexia cannot remove fault codes if the fault is still there. Sounds like a bit of a mess to be honest and I can't really advise on what the issue is being that the CAN enabled ECUs are on a data network with the master / controlling ECUs being the BSI and the engine ECU depending on the network. So it's possible the after-market equipment was not CAN compatible with your vehicle and may have caused some problems further up the line. Have you removed the whole thing and made good any splicing?
Yes it is disconnected. I only used power from one cable, so i hope the issue is that the system need to remove a code or reset the parking assist system. All other systems works with out a issue. I cant figure out what can cause the system not to work now based on the cable that i connected is removed. I did not split any cable harness etc, just use such plastic clip that is used to connect one cable to a excisting one.
Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by Fredrikrosen »

Might a BSI reset help?
User avatar
xantia_v6
Forum Admin Team
Posts: 9173
Joined: 09 Nov 2005, 23:03
x 866

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by xantia_v6 »

I don't think that a BSI reset would be much help, but will not hurt. Is there now power on the power lead that you spliced?
Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by Fredrikrosen »

xantia_v6 wrote: 23 May 2024, 08:15 I don't think that a BSI reset would be much help, but will not hurt. Is there now power on the power lead that you spliced?
Yes there is power, nothing is connected or similar. The car is in normal state so to say.

The reset is made by open side window, all systems off, wait 5 min, remove power from battery, wait 5 min, power back from battery, wait 1 min, side light on?
Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by Fredrikrosen »

Can i use this step by step guide on a -2022 Citroen?

viewtopic.php?t=61997
Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by Fredrikrosen »

The procedure did not work on my car, nothing changed.
User avatar
GiveMeABreak
Forum Admin Team
Posts: 38098
Joined: 15 Sep 2015, 19:38
x 5915

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by GiveMeABreak »

I think that your accessory equipment, once connected, has caused a problem up the line and is going to be potentially difficult to troubleshoot now. These later vehicles are very specific about connecting unapproved accessories, and Citroen state this very clearly in the owner's manual.

Maybe if you put everything back as it was and take it to your dealer under warranty - they may be able to sort it - but if you've also had a towbar fitted it may be a bit obvious and they may query this or the electrics.
Please Don't PM Me For Technical Help

Marc
Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by Fredrikrosen »

GiveMeABreak wrote: 23 May 2024, 19:32 I think that your accessory equipment, once connected, has caused a problem up the line and is going to be potentially difficult to troubleshoot now. These later vehicles are very specific about connecting unapproved accessories, and Citroen state this very clearly in the owner's manual.

Maybe if you put everything back as it was and take it to your dealer under warranty - they may be able to sort it - but if you've also had a towbar fitted it may be a bit obvious and they may query this or the electrics.
Might Lexia be able to remove any fault code? Or maybe the dealer have another diagnose, i suspect that the BSI needs to be accessed via a diagnose to remove or reset the system.

It seems odd that any hardware should take damagde only for taking power from a cable. I hope it is software related.
User avatar
GiveMeABreak
Forum Admin Team
Posts: 38098
Joined: 15 Sep 2015, 19:38
x 5915

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by GiveMeABreak »

Lexia (Diagbox in your case) can't remove fault codes if the underlying fault is there - it will just come back, but a proper Diagnostic with the system may provide some clues and is the obvious place to start to see if any of the ECUs are complaining or the BSI is upset about something.
Please Don't PM Me For Technical Help

Marc
Fredrikrosen
Posts: 12
Joined: 21 May 2024, 15:24
x 1

Re: Citroen C4 -2022 fuse diagram/parking assist issue

Post by Fredrikrosen »

GiveMeABreak wrote: 23 May 2024, 19:40 Lexia (Diagbox in your case) can't remove fault codes if the underlying fault is there - it will just come back, but a proper Diagnostic with the system may provide some clues and is the obvious place to start to see if any of the ECUs are complaining or the BSI is upset about something.
Ok.

Thanks for good support. :)