As shown in the following , the EWS3 / EWS4 with the Test , and supply 12V for the device, you will see the white indicator flashes, it indicates EWS3 is working ; after the EWS4 is supplied with 12V , you will see the indicator light fast flash, it indicates EWS4 is working . After supplying the but you can't see the white indicator flashes, it indicates EWS can't work , please check whether 0D46J or 2D47J is not welded , or maybe EWS is damaged, if it is so you could buy a used EWS and fix it by writing data. Put the programmed PCF7935 chip or EML electronic chip key near the middle of the test , and wait for 3 to 5 seconds, you will hear the relay in the EWS3 or EWS4 make a sound when working and see the red indicator flashes, it indicates the chip programming complete. EWS3 EWS4 Test For & Features: It is rechargeable, besides Key Programmer, for / EWS Test is the only device in the current market which able to charge for the rechargeable key. If you own the EWS and for / EWS Test , it means you own a set of advanced car key charger, and it can work with all rechargeable . It can 3 functions as follows without connecting for : 1, Able to test EWS3, EWS4 working or not 2, Able to test whether the PCF7935 chip or EML electronic chip key complete programming or not. 3, Able to test EML key electronic chip working or not, and test after fixing EWS data. Material: PC+Metal colour: As shown Package Contents: 1 x EWS Programmer Only the above package content, other products are not included. Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.