TM 1-1520-238-T-4 Change 1 6–139 6–65. HOD XMN 1 READING – DISPLAYS HIGH OIL TEMPERATURE 6–65 Tools: Nomenclature Part Number Tool Kit, Aircraft SC518099CLA01 Mechanic’s Tool Kit, Electrical SC518099CLA06 Repairer’s Personnel Required: 67R Attack Helicopter Repairer 68D Aircraft Powertrain Repairer/NDI 152FG Maintenance Test Pilot References: TM 1-1520-238-23 TM 1-1520-238-CL Equipment Conditions: Ref Condition TM 1-1520-238-CL Engine 1 operating WARNING Turn off power before detaching or attaching wires and connectors. High current 28 VDC or 115 VAC is present. Failure to do so could result in death or serious injury. 1. Check HOD display for XMN 1 oil pressure reading. Is reading 28 LB or lower? YES Go to paragraph 6–49 to troubleshoot HOD XMN 1 display. NO Go to step 2. 2. Check pilot caution/warning panel OIL HOT XMSN 1 indicator. Is indicator lighted? YES Go to paragraph 6–67 to troubleshoot OIL HOT MAIN XMSN 1 indicator. NO Go to step 3. 3. Check pilot caution/warning panel OIL PSI MAIN XMSN 1 indicator. Is indicator lighted? YES Go to paragraph 6–51 to troubleshoot OIL PSI MAIN XMSN 1 indicator. NO Go to step 4. 4. Check HOD display for XMN 1 oil temperature reading. Is oil temperature 121 C or higher? YES Go to step 5. NO Main transmission 1 oil temperature is not critically high. Go to paragraph 6–13. 5. Check heat exchanger 1 for obstruction and damage (TM 1-1520-238-23). Is damage present? YES Replace main transmission 1 heat exchanger (TM 1-1520-238-23). NO Replace NGB 1 lube pump (TM 1-1520-238-23). END OF TASK