TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download

TM 9-2320-280-20-1 REFERENCE INFORMATION PROTECTIVE CONTROL BOX/DISTRIBUTION BOX Change 1 2-235 Disconnect negative battery cable before disconnecting and reconnecting protective control box/distribution box harness. Failure to do so may result in injury to personnel or damage to equipment. Replace protective control box, refer to (para. 4-5). Replace distribution box, refer to (para. 4-5.1). WARNING Repair lead connectors, refer to (para. 4-85). Repair lead, refer to (para. 4-85). DIAGNOSTIC CHECKS (GO TASKS) (For Vehicles with protective control box/distribution box) OFF LED's 1, 3, 4, 6, 7, "ON''; Remaining LED's "OFF" If all LED's are "OFF", battery power is not available. If LED 3 or 4 is "OFF", replace the PCB/distribution box. If LED 7 is "OFF", body harness wire 57B is not grounded. LED's 1,2,3,4,5,6,7,8,11,13 "ON". LED 13 "OFF" after a few seconds (glow plug warm up time). LED 13 "OFF if engine is at operating temperature. LED 11 cycling "ON" and "OFF" (glow plug controller operatlon) LED's 9, 10, 12 "OFF". Release parking brake lever. LED 6 "OFF". Engage parking brake lever. LED 6 "ON". If all LED's are "OFF", no battery power is available. If LED 3 or 4 is "OFF", replace the PCB. If LED 7 is "OFF", harness wire 57B is not grounded If LED 2 is "OFF", and all glow plugs are serviceable, replace the PCB. If LED 5 is "OFF", replace the PCB is LED 13 is "ON". If LED's 5 and 13 are "OFF", the ignition switch is defective and/or harness wires 29A and 29C are defective. If LED 13 is "OFF" aud LED 5 is "ON" and the engine is not at operating temperature from a previous run, replace the PCB. The PCB is operational if the engine is at operating temperature from a previous run. If LED 6 is "OFF" and the parking brake lever is engaged the parking brake switch is defective or the wires in the body harness are defective If LED 8 is "OFF", replace the PCB. If LED 11 is "OFF", check the glow plug controller. If the glow plug controller is functioning properly, replace the PCB. LED's 1, 2, 3, 4, 5, 6, 7, 8,13 "ON"; remaining LED's "OFF" LED 13 "OFF" after a few seconds (glow plug warm up time). LED 13 "OFF" if engine is at operating temperature. LED 6 "OFF if parking brake lever is released. LED 6 "ON" if parking brake lever is engaged If LED 2, 3, 4, or 8 is "OFF", replace distribution box. If LED 7 is "OFF", body harness wire 57B is not grounded If LED 5 is "OFF", replace distribution box if LED 13 is "ON". If LED's 5 and 13 are "OFF", the ignition switch and/or harness wires 29A and 29C are defective. If LED 13 is "OFF" and LED 5 is "ON", and engine is not at operating temperature from a previous run, replace distribution box. Distribution box is operation if engine is at operating temperature from a previous run. If LED 6 is "OFF"and the parking brake lever is engaged the parking brake switch and/or the wires in the body harness are defective. LED 10 momentarily "ON" and then remains "OFF" (starter motor frequency lockout). If LED 11 and 13 remain "ON" or engine does not crank; check battery voltage; charge is low. If LED 10 does not momentarily come "ON" and then stays "OFF", replace PCB. LED 10 momentarily "ON". If LED 13 is "ON or engine does not crank; check battery voltage; charge is low. If LED 10 does not momentarily come "ON" and then stays "OFF'', and ignition switch is operating properly, replace distribution box. LED's 1,2,3,4,5,6,7,8,9,12 "ON" LED 11 cycling "ON" and "OFF" (glow plug controller operation): "OFF" time interval increases as engine warms up. LED 11 "OFF" (when engine is at operating temperature). LED 11 may remain "OFF" (when engine is at operating temperature from prevlous run). LED 13 "OFF" Release parking brake lever. LED 6 "OFF". Engage parking brake lever. LED 6 "ON". If LED 2, 3, 4, 5, or 8 is "OFF" and all glow plugs are serviceable replace the PCB. If LED 7 is "OFF", the body harness wire 57B is not grounded. If LED 9 is "OFF" and LED 12 is "ON", replace the PCB. If LED's 9 and 12 are "OFF", there is no alternator output (alternating current tap) available and/or the engine harness wire 2A is defective. If LED 11 is "OFF" and the engine is not at operating temperature, check the glow plug controller. If the glow plug controller is functioning properly, replace the PCB. LED's 1, 2, 3, 4, 5, 6, 7, 8, 12 "ON", remaining LED's "OFF" LED 6 "OFF" if parking brake lever is released. LED 6 "ON" if parking brake lever is released If LED's 2, 3, 4, 5 or 8 is "OFF" replace distribution box. If LED 7 is "OFF", body harness wire 57B is not grounded If LED 12 is "OFF", there is no alternator output (alternating current tap) available and/or engine harness wire 2A is defective. RUN - (PCB) START (ENGINE CRANKING- PCB) (ENGINE NOT RUNNING- PCB) RUN - (Distribution Box) (ENGINE NOT RUNNING- Distribution Box) START (ENGINE CRANKING- Distribution Box) RUN (ENGINE RUNNING- PCB) RUN (ENGINE RUNNING- Distribution Box) NOTE This analyzer requires all glow plugs be serviceable and the batteries fully charged in order to operate properly. Prior to performing diagnostic checks ensure these two items are checked. If either of these two items are found to be faulty, repair/replace prior to beginning checks. Failure to do so will cause the analyzer to give false readings, therefore causing the needless replacement of serviceable components.