Locate the BSI unit (typically behind the glovebox or under the dashboard on the driver’s side in left‑hand drive vehicles). Open the BSI casing and visually inspect all fuses on the board. Pay special attention to any 10A fuses that supply power to the key reader or immobilizer. Replace any blown fuse.
Signal failure between the transponder/key fob and the internal antenna/reader
Another owner reported that after driving for 15–20 km, the "engine failure" message would appear, accompanied by codes B173D, B1808, B1137, and B1744. All systems appeared to work normally. The forum consensus pointed to a as the most likely cause, because low voltage or poor earthing can trigger a cascade of unrelated codes.
Passenger Airbag Deactivation Switch – Circuit Malfunction / Inconsistent Signal b173d peugeot work
Switch off the ignition, close all doors, and wait 3 full minutes for the BSI to enter sleep mode.
Even if it cranks, low voltage can cause ECU communication failures. 4. Symptoms
The passive antenna coil surrounding the mechanical ignition lock barrel (or the slot reader in hands-free models) is highly susceptible to wear and internal shorts. If the antenna wire degrades, it cannot emit the magnetic field needed to power up and read the key’s electronic transponder chip. 3. Battery Voltage Drops and Electrical Spikes Locate the BSI unit (typically behind the glovebox
After addressing any voltage or fuse issues, clear all fault codes using a compatible diagnostic tool (Diagbox is preferred, but many generic OBD2 scanners can read and clear manufacturer‑specific codes). Then drive the vehicle for 15–20 km. Re‑scan to see if B173D returns. If it does, note whether it appears alone or with other codes.
: Check the 10A fuse inside the BSI unit (typically behind the glovebox), as a blown fuse here can cut power to the immobilizer circuit. Summary of Possible Fault Meanings Code Detail Likely Symptoms B173D:86 Identifier Invalid Key detected but not recognized as "correct" for this car. B173D:00 Identification Fault General failure to see any key signal at all.
Finally, . The fix might be as simple as repairing a broken wire in the rubber boot between the door and the chassis (a classic Peugeot failure point) or as involved as reprogramming a replacement BSI—a process that requires downloading the vehicle's specific configuration from Peugeot’s servers and pairing it with the immobilizer transponder key. Replace any blown fuse
: A weak battery in your remote is the most common cause of intermittent recognition.
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