Ford Mustangs commonly show 3 flashes on its turn signal when changing lanes. You can actually increase or decrease the default number of flashes on your Mustang using FORScan, this is how you do it:

Step 1: 

Locate your vehicle's SCCM module.

Step 2: 

Apply the following code changes based on your prefered number of flashes on the following line: 

724-01-01 : xxxx x?xx xx

Change: ?

To: 0-3=1 flash, 4-5=2 flashes, 6-7=3 flashes, 8-9=4 flashes, A-B=5 flashes, C-D=6 flashes, E-F=7 flashes

Special thanks to the FORScan community for compiling all of these codes.

For more information on how to properly set it up, check this Mustang FORScan code document built by the FORScan community. 

To successfully change the number of turn signal flashes on your Ford Mustang with FORScan, you will need a reliable OBD2 device. Check out these OHP OBD2 devices that work flawlessly with FORScan.

Note: For FORScan coding modifications, we recommend using the OBD2 USB adapter for it provides a more stable connection.