ENGINE,  FUEL,  EXHAUST  AND  COOLING 4-1. Engine    Troubleshooting. TM   10-3930-643-20 TROUBLESHOOTING AND MAINTENANCE. MALFUNCTION TEST OR INSPECTION CORRECTIVE   ACTION f . LOW  OIL  PRESSURE. Step   4. Check   that   oil   pressure   gage   and   sending   unit   are   operating properly. Refer   to   STE/ICE   Test   35,   page   4-9. If   gage   is If   gage   is If   sending If   gage   is f a u l t y ,    r e p l a c e . Refer   to   paragraph   5-15. operating   properly,   notify   Direct   Support   of unit   is   faulty,   replace. Refer   to   paragraph operating   properly,   notify   Direct   Support   of problem. 5-40. problem. 4-5