Using Pico's Keyless Entry Carrier Signal Detector (TA330)

The TA330 is a 3 meter long lead and detector intended to allow a technician to sense the presence of the keyless entry carrier frequency (125 - 140kHz for most manufacturers) - but without decoding for security reasons. Designed for short-range operation, the technician can check each pickup coil in turn to find a faulty unit.

This video shows how: 
https://youtu.be/80td6R52hwg

The product is here:  https://www.saelig.com/product/ta330.htm