TM 10-6640-239-13 4-55 4-25.    ENVIRONMENTAL CONTROL UNIT REMOTE CONTROL. This task consists of: a. Remove b. Install INITIAL SET-UP Tools Required General Mechanics Tool Kit, (Appendix B, Section III, Item 1) General Safety Instructions WARNING ELECTRICAL SHOCK Before  performing  any  maintenance  actions  on  electrical  equipment,  ensure  all electrical power has been turned off.  Failure to comply with this warning may result in serious injury or death. REMOVE Remove Environmental Control Unit (ECU) Remote Control.  See Figure 4-15. a. Position ECU mode switch (1) to OFF. b. Position Power Panel No. 2 circuit breakers A15CB1, A15CB2, A15CB3, or A15CB4 to OFF. NOTE To prevent damage to ECU control connector pull ECU control straight out. c. Loosen captive screw (2) and remove ECU control (3) from panel (4). INSTALL Install Environmental Control Unit (ECU) Remote Control.  See Figure 4-15. a. Install ECU control (3) into panel (4) by ensuring ECU control connector is aligned with mating connector and secure by tightening captive screw (2). b. Position Power Panel No. 2 circuit breakers A15CB1, A15CB2, A15CB3, or A15CB4 to ON. c. Position ECU mode switch (1) to an operational mode and verify ECU operation.