508 1.6 e-hdi B1003-00 Fault and Start Stop Problem

[resulmk]

Hello everyone,I have a 2012 model 508 vehicle. After the installation of the PX5 android multimedia system, my start-stop system stopped working. During the installation, the car had entered economy mode and a fuse related to the sound system had blown. After replacing it, my sound system started working. I expected the start-stop system to work the next day as the battery voltage would increase due to the car being in economy mode, but it didn't work. I removed the battery and left it on charge for a day, but it still didn't work. I bought a new battery and charged it, but it still didn't work. When I checked with Diagbox, I encountered the issue shown in the photo. Diagbox only shows the B1003-00 error, but this error existed before these issues occurred.Can you help me?

[GiveMeABreak]

This is referring to the voltage maintaining device / ultra-capacitor system if fitted to this vehicle, and not the vehicle's main battery. This Stop Start system on older vehicles has a power accumulator and ECU hidden usually behind the front left wing for the stop start system. Be very careful not to attempt to touch or remove this as it contains high voltages and needs to be properly discharged before removing it.