backlight instrument cluster problem after swapping ECUs

Hi,
I have swapped ECU and BSI from Peugeot 1007 to my C3. It has solved my issue with ECU part, but I have encountered a new one - quite annoying little problem.
Backlight on instrument cluster is having switching on and off depending on speed when lights are turned on.
I have DRL installed, they are independent to Citroen BSI etc. They turn on always when power steering fuse is in high state. When I drive only on DRL (so low beam is off) this issue doesn't happen. But when I turn low beam on and accelerate over 30 km/h only speed is shown (petrol indicator, mileage, daily mileage are off and rev counter backlight is turned off). This toggles when any button (cruise control ON/OFF, cruise control +, cruise control -, cruise control pause, button on right arm - this for wipers) is triggered. I don't have screen and radio.
I can change this state by clicking left button on instrument cluster, but it changes when button is pressed more than 5-10 times.
I have no idea why it is like that, configuration is 1:1 to my old ECU + BSI set and everything else works and doesn't show any error messages.
Does anyone have experience with Peugeot backlight dimming algorithm? Maybe something like night ride is active? I didn't see a similar setting in Peugeot Planet or Lexia software...
PS Pressing and holding the left button on instrument cluster for over 10 sec didn't help - I tried this on ignition, turned on engine and while driving.
Best regards!

Hi

Use lexia to reconfigure the new ECU (BSI?) to match the configuration of the C3 and not the donor.

Hi,
For me it would be to programm new ECU to old BSI, because old ECU wasn't working properly.
But I would rather not really follow this solution to mix up mileage and immobiliser. Do you know any other solution?
Would you at all recommend (having LEXIA of course) to programm new (used) ECU to existing BSI? I have read many posts (not only on this forum), that it is highly recommended to change whole set (at bare minumim set ECU + BSI).
What are your reflections on this topic?
Best regards

odoedel wrote: ↑Sun Mar 20, 2022 6:44 pm What are your reflections on this topic?

You implied that you swapped either the ECU or the BSI and not both and the engine still starts, so I guess you have some dodgy IMMO OFF?

You can't start the car by swapping just the BSI or the ECU as they are paired and must be fitted as a pair, unless someone has hacked the firmware in either or both. Who knows?

You also need a paired transponder key part to start and these are included in the kit.


Whatever you do, the new BSI will need configuration with lexia to match the ECUs in the recipient car because the BSI has donor programming from a different model.

Hi,
Sorry for my English, it's not my first language.
I wrote, that I swapped ECU and BSI. I also used key transponder from ECU/BSI set to match ECU immobiliser.
Every single component (ECU, BSI, key) is from donor car.
I configured BSI, ECU and ECU present (part from BSI configuration that lists what is available on vehicle) in the same way as it was originally on my C3.
The problem is that there is no mention of any backlight dimming setting in all of mentioned configuration.
I don't have any hacked component (like IMMO OFF, resorted to factory etc).
I also tried to connect Peugeot 1007 instrument cluster, but it went horribly wrong - nothing was working on instrument cluster.
Sorry if I stated something that wasn't clear for you.
Best regards.

odoedel wrote: ↑Sun Mar 20, 2022 10:36 am I don't have screen and radio.

Have you turned those items off (not present) in the BSI configuration? It wont like it if you tell it things are there when they aren't.

Ozvtr wrote: ↑Mon Mar 21, 2022 8:59 am

odoedel wrote: ↑Sun Mar 20, 2022 10:36 am I don't have screen and radio.

Have you turned those items off (not present) in the BSI configuration?

Hi,
Yes I have. I have purged every single point according to old configuration in those three configuration parts.
Later I also tried to use Customer option to uninstall radio. But it didn't help - only multifunctional display was set to present. Thank you for that PSA Group. Of course later on I changed it back to absent.
Best regards.

I don't know about the MK2 (facelift post 2005) but the pre facelift instrument panel has "black panel" mode where any of the illuminated panels are turned off. I.E. the instrument panel and the center display.
The speed is displayed but not lit up. For an auto car the selected mode is displayed, the turn indicators flash and any of the warning lamps illuminate but everything else is off.
It's activated by the instrument panel dimmer button. Bright-dimmer-dimmer-dimmer-black panel-bright-dimmer-dimmer and so on.

It used to work like this too in my Citroen (post facelift) but after BSI and ECU swap it stopped working like this.

Hello everyone,
I had some spare time and I used it to diagnose what is the problem with this weird backlight issue.
The sad information is, that I still don't know.
But the good news is, that as mentioned before this +/- buttons works very well. While low beam lights are on, this button regulates backlight power.
On screen below you can see variable Lighting level. It changes with backlight on instrument cluster.
But when I pushed a button on COM 2000 unit (Cruise control + or CC - or CC Pause or Wipers on or Direction indicator on or pushbutton on wipers lever), this variable didn't change, but backlight on instrument cluster did.
I have no idea what is going on. Maybe this is on different level - maybe it's not operated with CAN bus, but some electrical magic from PSA is then steering.
I thought that maybe I shall update software on BSI to match it from car that it was taken to my Citroen. Well I can't - it was from Peugeot 1007 and SW version is 15.03 and it is not possible to change it to Citroen C3 software 09.03.
If anyone has an idea what could cause this issue, please let me know.
Thank you for previous support on this topic.
Best regards!