DiagBox is the manufacturer diagnostic and repair software used for Peugeot, Citroën and DS vehicles. The PSA independent-operator installation guide describes VIN-specific access to ECU diagnosis, repair procedures and vehicle data also used by authorised repairers. Coverage and features depend on the vehicle and subscription. PSA DiagBox installation guide (2017).
Earlier systems
For supported older vehicles, DiagBox can launch Lexia for Citroën and Peugeot Planet 2000 (PP2000) for Peugeot. These names refer to diagnostic software for the respective marques, and do not mean all cars work with the same software release. SILIM PSA activation guide.
Opel and Vauxhall
Opel's independent-repairer conditions cover both Opel and Vauxhall. They distinguish PSA-conception vehicles managed by DiagBox from legacy vehicles managed by GDS2 or Tech2Win; programming access differs between these groups. Match the diagnostic system to the actual vehicle. Opel and Vauxhall diagnostic conditions, November 2025.
Interfaces and cloud software
DiagBox connects through a vehicle communication interface (VCI). Citroën lists DiagBox and DiagBoxCloud, and identifies certified interfaces including the ACTIA XS 2G and PSA interface. The manufacturer states that with a standard SAE J2534 Pass-Thru interface only reading functions are guaranteed, whereas a PSA interface offers all software functions. Exact capability, current support, subscriptions and authorisation should be checked against the vehicle and current service information. Citroën diagnostic conditions, November 2025.
See also Peugeot diagnostic tools and Citroën diagnostic tools.