TM 9-2320-302-20 0010 00-1 ELECTRICAL SYSTEM TROUBLESHOOTING 0010 00 Table 1. Electrical System Troubleshooting Procedures. MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION Engine Brake System Engine   Brake   (Jake   Brake)   Inoperative   or Operates Erratically. 1.    Remove fuse panel cover and check engine brake 15A fuse. Replace   fuse   as   necessary   (WP 0071 00). 2.    With  ignition  ON  and  engine OFF  or  at  idle,  press  Check Engine Button, observe Check Engine Light (CEL). a. If CEL comes on and stays on, perform step 3 and read Active Flash Codes. b.    If  CEL  come  on  for  up  to five seconds and then turns off, perform step 3 and read Inactive Flash Codes. c. If   CEL   comes   on,   but   is erratic or intermittent, refer to DDEC system fault code, 10.4 (WP 0007 00). 3.    Connect Diagnostic Data Reader  (DDR)  to  Diagnostic Data Link (DDL) connector. Perform DDEC system troubleshooting.  Refer  to  section number  that  matches  flash  code logged (WP 0007 00). Engine Fan Circuit Engine Fan Does Not Operate or Fails to Start at 190°F - 210°F (87°C - 98°C). 1.    Remove fuse panel cover and check fan/modulator 15A fuse. If defective, replace 15A fuse (WP 0071 00). 2.    Check fan clutch air lines and hoses for leaks. If  leaking  or  a  damaged  hose  or line  is  found,  replace  (WP 0049 00). 3.    With  ignition  ON  and  engine OFF  or  at  idle,  press  Check Engine    Button    and    observe Check Engine Light (CEL). a. If CEL comes on and stays on, perform step 4 and read Active Flash Codes. b.    If  CEL  come  on  for  up  to five seconds and then turns off, perform step 4 and read Inactive Flash Codes. c. If   CEL   comes   on,   but   is erratic or intermittent, refer to DDEC system fault code 10.4 (WP 0007 00). 4.    Connect Diagnostic Data Reader  (DDR)  to  Diagnostic Data Link (DDL) connector. Perform DDEC system troubleshooting.  Refer  to  section number  that  matches  flash  code logged (WP 0007 00).