Change the key fob battery out for a fresh, high-quality CR2032 battery.
The engine does not start, or you receive a "Key Not Detected" message on the dashboard, even if the key is inside the car.
Switch the ignition on, hold down the lock button on your key fob for 10 seconds to resynchronize the remote, then attempt to start the engine. Step 4: Check the 12V Vehicle Battery Health
Intermittent failure to lock or unlock the vehicle using the remote. b173d peugeot
Indicates power delivery to structural ignition circuits was cut short, starving key-reader modules. Driver's door presence detection error.
Yes, absolutely. A weak battery in your key fob is a surprisingly common cause of the B173D fault code. The BSI may not receive a strong enough signal to properly identify the key. Replacing the key fob battery is a simple and inexpensive first step.
In the PSA Group (Peugeot/Citroën), fault codes starting with "B" refer to systems. The B173D specifically indicates an issue with the Hands-Free Remote Identification . Change the key fob battery out for a
The control unit (a small black or silver box mounted on the rocker cover or near the injectors) is a solid-state relay. It can fail for cylinder #4 only. If the MOSFET (transistor) controlling Cylinder 4 burns out, you will get a B173D code even with a perfect glow plug and wiring.
Unplug the electrical connector from the glow plug control unit and test each glow plug directly at the unit's connector pins. You need the pinout diagram for your specific Peugeot engine (DV6 or DW10). For cylinder 4, you should see approximately 0.6 to 1.2 Ohms .
The B173D code can range from a minor maintenance issue to a significant electrical failure: Step 4: Check the 12V Vehicle Battery Health
If these steps do not work, it is highly likely you have a faulty antenna or a BSI module communication failure, which will require specialized diagnostic equipment to fix.
: Heavy electrical interference from close aftermarket dashcams, magnetic phone mounts, or local radio towers can break the connection to the key reader. Step-by-Step Troubleshooting and Diagnostic Procedure
The exact designation for B173D in official PSA diagnostic framework tools like or Lexia reads:
