B1600: PATS transponder ignition key signal not received
Drive carefully. Get it checked within a week or two.
Can I drive with B1600?
Yes, but drive carefully and get it checked soon. The anti-theft immobilizer did not read your key chip; engine will crank but not start. Meaning can vary by make and model.
What does B1600 mean?
B1600 stands for PATS Transponder Ignition Key Signal Not Received.
Symptoms you may notice
- Interior electrical accessory malfunction (locks, wipers, or climate buttons)
- Battery voltage warning or rapid battery drain while parked
- Key chip not recognized warning chime
How much does it cost to fix?
Repair costs for code B1600 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Damaged or unprogrammed ignition key chip
- Failed immobilizer transceiver antenna ring around key cylinder
- Metal keychains or remote fobs interfering with RFID signal
- Weak vehicle battery during key read
What to do next
- Try using a second/spare ignition key.
- Remove heavy metal keyrings or other vehicle fobs from your keychain.
- Check if the padlock/security light on the dashboard is blinking rapidly.
Last updated: October 2026
Related codes
General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.
About this code
Code B1600 is Ford's passive anti-theft system (PATS) code for an unread key. The receiver coil around the key barrel cannot read the RFID transponder chip inside the key head. The engine may crank endlessly without firing. Using a spare programmed key usually resolves it.