TM-9-1200-215-34&P Technical Manual for M109 Automatic Fire Control System (AFCS) Download
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TM 9–1200–215–34&P 4–3 Section IV – MANUAL TROUBLESHOOTING Page Page General 4–3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Functional Description 4–3 . . . . . . . . . . . . . . . . . . . . . Initial Fault Indication 4–4 . . . . . . . . . . . . . . . . . . . . . . Manual Troubleshooting Procedures 4–5 . . . . . . . . . 4–8. GENERAL This chapter contains information on checks and corrective actions required to isolate defects in the PDIU, and correct the defects by means of maintenance. The manual troubleshooting shall begin with a fault or symptom and lead to a single fault isolation of the problem. In cases where the maintenance must be performed at a higher level, the description will note “Forward PDIU to Depot”. 4–9. FUNCTIONAL DESCRIPTION a. The purpose of the PDIU is to perform prognostic and diagnostic functions on a weapon system. The PDIU tests, detects faults, and fault isolates Line Replaceable Units (LRUs) in the Electrical System, Automatic Fire Control System (AFCS), Vehicle Hydraulic System, and Gun Position System. Figure 4–1 is a block diagram showing major PDIU signal flows during operation. VMS DRUH 768K MEMORY CCA SIGNAL PROTECTION MUX DC/DC CONVERTER (POWER SUPPLY) EMI FILTER CCA PRESSURE TRANSDUCER 1553 I/F PROCESSOR DIAGNOSTICS PROGNOSTICS I/O CCA CURRENT SHUNT FLOW METER 1553 PCU DU ACU PWR BIT VMS BACKPLANE Figure 4–1. Prognostic/Diagnostic Interface Unit Block Diagram