For a couple of months now, the ABS on my 2014 FJR has been giving me grief, every now and again, it will start flashing the ABS warning light at me while riding. At first, it was mainly when I had been riding twisty mountain passes where I work the brakes real hard, but recently it started occurring any time. It would blink the ABS light for a while, then stop, or stop every time I stopped and re-started the bike.
The manual says that, if the ABS light comes on permanently, there is a definite failure in the ABS system, but if it blinks, the ABS is operational, but the ABS ECU is unhappy with one of it's input signals, but which signal.
I did some reading of the manual, and discovered that I needed special tool P/N 90890-03149, Test Coupler Adapter, in order to read the fault codes in the ECU memory, and of course I don't have one. So, I did a bit of searching on the internet and discovered a simple jumper lead with 2 crocodile clips could be used in lieu of the special Adapter, so I went into the local electronics shop and bought some jumper leads.
The next problem is that the ABS Coupler connector on the bike has 4 pins, and you need to jump 2 of them, but which 2? Further searching found that it is the Black/White and Sky Blue wires that need to be jumped, the other 2, Blue/Black and Blue/Red are not required for this procedure.
I then removed the inner fairing panels and found the ABS Coupler connector mounted near the positive terminal of the battery. I dismounted the connector, jumpered the 2 test pins, and was then able to read the fault codes from the ABS ECU.
I got ABS - 11, 23, 25, and 41 codes. The manual says 11/25 refer to the front wheel rotation sensor, 23 refers to the Brake Light being faulty, and 41 could be a brake dragging. The 11/25 codes seemed the most likely cause of my problems, so I went to the Front Wheel Sensor and removed the sensor from it's housing, just one screw holding it. Sure enough, there was corrosion between the sensor mounting plate, and the housing, probably causing a bad earth for the sensor. I scraped the corrosion off and polished the metal with Scotch-Brite, then applied some CRC 5.56 Penetrant / Lubricant and re-mounted it. I also did the same to the rear wheel sensor and found corrosion there as well, but not so much.
I then deleted the fault codes and reassembled the bike. This morning, I took the bike on a 200 Km test ride, and the ABS light didn't blink at me at all, I hope that's the end of the problem. So, the moral of the story is, get those sensors off every now and then, and clean any corrosion off.