We have a Toyota model 5FBCU25 forklift that is having the CO code issue and it doesn't move in forward or reverse but everything else works. The forklift mechanic came and checked everything out and couldn't find any problems and said the transistors were bad. We ordered all 3 new transistors along with the heat transfer silicone and installed them ourselves but they only lasted a month before they went bad again. we replaced them again but only lasted about 30 minuets this time, What else could be causing this issue? I pulled the records and this same issue happened in 2016 and all three transistors were replaced along with the Diode 90892-01022-71 and 2 contactor assy. 24420-13300-71, $5,577.00 worth of repairs