Swoop I have a unit p6000 hiving a similar code 85 not 87 my particular unit only throws the no forward code when unit is running and working hard after 1 hour. Truck cools down and no problems leave customer location and call back after unit is running after a while and code returns. My coils ohm out at 6 I'm assuming my forward and reverse solenoid is getting hot and failing what is your input in this would you replace the sokenoid to save the time troubleshooting as my unit will not act up again to confirm halt ages a sokenoid