B173d Peugeot Site

: The small ring around the ignition barrel that "reads" your key might be faulty or disconnected.

: Often the simplest culprit, a dying battery in your remote can prevent the reader from "seeing" the key.

B173D is a manufacturer-specific diagnostic trouble code (DTC) that is directly related to your Peugeot's security and immobilizer system. The official definition states it is a .

Lower the driver's window completely, switch off the ignition, and remove the key. b173d peugeot

Understanding and Fixing Peugeot/Citroën Fault Code B173D: Keyless System Failures

: Replacing the battery in your remote is the first recommended step. Immobilizer Antenna

Peugeot BlueHDi engines are notorious for carbon buildup. Because the glow plugs extend into the combustion chamber, they become crusted with hard, black carbon. This carbon can: : The small ring around the ignition barrel

: The engine may fail to crank or start because the immobilizer remains active.

In Peugeot and Citroën vehicles, is not a feature but a specific diagnostic fault code (DTC) related to the vehicle's security system Fault Code Definition indicates a failure in identifying the mechanical/electronic key

This code indicates that the car's primary body control computer, known as the (Boîtier de Servitude Intelligent), has experienced an interruption or failure in its communication with the key fob. This communication breakdown is often the root cause of the immobilizer system malfunctioning. The official definition states it is a

In Peugeot and Citroën (PSA) vehicles, diagnostic trouble code (DTC) points directly to an immobilizer or key recognition failure . Formally logged by the Built-in Systems Interface (BSI)—the central body control module—the error is defined as a fault in identifying the mechanical/electronic key or the hands-free remote control present in the reader .

: The vehicle may refuse to lock or unlock via the remote fob button or hands-free proximity sensors.

The issue can range from simple battery problems to hardware failures: Weak Key Fob Battery

or the hands-free remote control. It is a body-related code ("B" prefix) often logged by the Built-in Systems Interface (BSI)