If you’ve worked through this guide and the B173D code persists, it’s time to consult a Peugeot specialist with access to Diagbox or the manufacturer’s Service Box diagnostic software. These tools can test the key transponder, monitor live data from the BSI, and access technical service bulletins specific to your vehicle’s VIN range.

Models equipped with keyless entry or push-button start will display a distinct remote control error warning.

A healthy battery should read resting. If it reads 12.2V or lower, charge or replace the battery, clear the codes, and attempt to start the vehicle. Step 3: Perform a Hard BSI Reset