95 Freightliner Fld Cummins M11 Fault Codes

Hi, I own a 95 Freightliner FLD120 with a Cummins M11...I have a couple of codes showing up in my old road relay screen...First code reads CNTRL THRTT S017 VOLT<NORM F04...Second code reads BOOST PRESS P102 VOLT<NORM F04...I also have a third code wich only comes on when I turn truck on which reads COOLANT LEVL BELOW NORM P111 F1...If anyone can assist me in telling me what these codes mean and maybe which parts I need to change I would be more than thankful...