C4 Grand Picasso - Parking & Blind Spot Issues After BSI/Dash Replacement

[santosc]

Hi everyone,

2015 Citroën C4 Grand Picasso automatic, 1.6 diesel, VIN VF7**************[VIN obfuscated, can be read by forum staff].

I recently had to replace the BSI and the dashboard.
I bought used parts from a scrapyard for the replacement.

After the swap, I noticed that some systems are no longer working, such as:
– Parking assistance
– Blind-spot monitoring

Here are the label details for the original and used BSI:

Original BSI:
9806687980 01 BSI-Q04-01
1/ 15097/ 353040221 / 15036
S180204004 B

NEW Used BSI (NEW for me):
9806687980 01 BSI-Q04-01
00/ 16715/ 363087571 / 16076
A2C38848700

And here are the dashboard details:

Original DASHBOARD:
9815286180 24/10/17
503005510117A-00 + 5-00arat HW:PRS8
MM-CMB-CIROCCO B78-CEM01 SW:9.4

NEW Used DASHBOARD (NEW for me):
9815286180 15/06/16
503005510117A-00 + 5-027f6S HW:PRS8
MM-CMB-CIROCCO B78-CEM01 SW:9.4

I configured everything manually using Diagbox, but parking assistance and blind-spot monitoring are still not working.

I'm wondering if it's a configuration issue, if I may have damaged a cable during the process, or if the new BSI or dashboard might be incompatible.

Has anyone experienced something similar? Any suggestions on what might be wrong?

Thanks

[mickthemaverick]

As a first move I'd double check the plugs into the new units to be sure you haven't got a bent or misplaced pin in one of them and that they are firmly connected. Then check the wiring you have moved around for fractures or damage. After that it will be a diagnostic job. Good luck

[PaulC5]

Maybe you could check if the parts you have put on are from a car that had the options that are now missing. It might be if they were not on the other car you may have to do without.

You might be able to find out if you have the vin of the other car and then asking at a dealer for the build sheet (vehicle characteristics) for your car and the other car so you can compare them.

[wheeler]

Out of curiosity why were these components replaced? Did you have the BSI Virginised?
Have you checked the configuration of the instrument panel to see if there is any manual configuration for these systems in there?

[santosc]

Out of curiosity why were these components replaced? Did you have the BSI Virginised?
Have you checked the configuration of the instrument panel to see if there is any manual configuration for these systems in there?

I bought the car used at a very low price, already with some issues. The BSI needed to be replaced, and the dashboard had display problems and was shutting down intermittently.

[santosc]

As a first move I'd double check the plugs into the new units to be sure you haven't got a bent or misplaced pin in one of them and that they are firmly connected. Then check the wiring you have moved around for fractures or damage. After that it will be a diagnostic job. Good luck

Thanks, I will definitely do a full check on the plugs and wiring as you suggested.
If I knew where the Park Assistance and Blind Spot Monitoring components are located, I would check them directly as well.
Does anyone know their exact location in the car?

[santosc]

Maybe you could check if the parts you have put on are from a car that had the options that are now missing. It might be if they were not on the other car you may have to do without.

You might be able to find out if you have the vin of the other car and then asking at a dealer for the build sheet (vehicle characteristics) for your car and the other car so you can compare them.

I bought the parts from used parts marketplaces like rrr.lt and b-parts.com.
I can probably get the VIN of the donor car, but unfortunately the sellers don’t reply when I ask whether the original car had those options (like Park Assist or Blind Spot Monitoring).

[santosc]

I found out that the Blind Spot Monitoring works on the left side — the light turns on in the left mirror, and during Diagbox actuator tests, only the left side responds.
But the right side does not work at all — neither the mirror light nor any response during Diagbox testing.

Maybe that’s also why Park Assistance isn’t working — possibly because the system detects a fault in the Blind Spot Monitoring and disables related systems.

Does anyone know which wire, connector, or BSI pin is responsible for the right-side Blind Spot Monitoring?
Or which cable I should trace to investigate this issue?

I also noticed that Keyless Entry is not working on the right side either — I can lock/unlock the car by touching the left front door handle, but it doesn’t respond on the right side.


Thanks

[mickthemaverick]

Since you have 2 faults n the drivers door I would suspect the cable loom that enters the door from the wing. It is a prime suspect area for damage and needs a thorough check for chafing or broken wires. Does the mirror adjusting work?

[santosc]

Since you have 2 faults n the drivers door I would suspect the cable loom that enters the door from the wing. It is a prime suspect area for damage and needs a thorough check for chafing or broken wires. Does the mirror adjusting work?

The mirror adjustment works fine, and the mirrors also fold automatically when I lock the car.

I ran the actuator test in Diagbox for the Blind Spot Monitoring lights, and both the left and right mirror lights turn on properly.
I also tested all 12 parking sensors manually, and they all respond correctly.

While driving, the Blind Spot Monitoring works fine on the left side (driver’s door), but it doesn't work on the right side (passenger door).
Also, the Keyless Entry is not working on the right side either.