B173d Peugeot Work ((better)) Review

While the car might start and drive initially, the B173D code indicates a fault in the immobilizer system. The vehicle could shut down unexpectedly or refuse to restart after you turn it off, leaving you stranded. It's best to diagnose and fix the issue as soon as possible.

If the key and BSI lost sync due to a drained battery:

Bad earth connections—for the BSI, the engine ECU (engine management computer), or the ABS (anti‑lock braking system) unit—can cause erratic signals and communication failures. This is especially common on vehicles that have seen corrosion or previous repairs. b173d peugeot work

Once the repair is complete:

In rare cases, the BSI itself may have an internal hardware failure or corrupted software. However, newer‑generation BSIs (post‑2015) are generally more reliable than older units. While the car might start and drive initially,

If diagnostics confirm the BSI is physically failing (corrosion or component burnout), it must be replaced.

Remove the lock assembly from the door. Use a multimeter to test the pins on the lock connector (refer to a wiring diagram for your specific model, typically 4 to 6 pins): If the key and BSI lost sync due

In the context of Peugeot’s (PSA Group) diagnostic architecture, is a manufacturer-specific body control code. Unlike generic OBD2 codes (P0300 for misfire, for example), B-codes relate to internal body electronics, lighting, and power management.

: A temporary communication error within the BSI can lead to "unexpected reinitialization" and key recognition failure.

A corrupted BSI often causes false B173D codes. You can clear temporary electronic glitches by performing a manual hardware reset without specialized tools.

From extensive forum discussions and repair case studies, the following root causes are most frequently identified: