Where is the OBD port located on an older Volkswagen Passat?

[VonCooper]

Volkswagen's OBD port is located next to the battery in the Passat B5, allowing external diagnostic computers to connect to the Passat B5's electronic control unit for maintenance operations. Common functions of OBD: Continuously monitor the faults of components and systems to ensure that the vehicle's emissions do not exceed OBD regulatory requirements throughout its lifespan. When an emission-related fault is detected, the OBD system can alert via the MIL (Malfunction Indicator Lamp) on the dashboard. This ensures that faulty vehicles are repaired promptly, reducing emissions. How the OBD system works: The OBD system continuously monitors the engine's operating conditions to check if the vehicle's emissions exceed standards. If they do, it immediately issues a warning. When a system fault occurs, the MIL or Check Engine warning light illuminates, and the Powertrain Control Module (PCM) stores the fault information in memory. The fault codes can be retrieved from the PCM using a specific procedure. Based on these fault codes, technicians can quickly and accurately identify the nature and location of the fault.