TM-9-2320-387-24 HMMWV Direct Support & General Support Maintenance Manual Volume 2 Download
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Change 1 14-7 TM 9-2320-387-24-2 MALFUNCTION TEST OR INSPECTION and piston rings (TM 9-2815-237-34). END OF TESTING! 14. CRANKCASE OIL DILUTED Step 1. Remove and test fuel injection nozzles. Replace worn fuel injection nozzles (para. 16-3). Step 2.1. Check defective fuel injection pump. Replace defective fuel injection pump (para. 16-6). Step 2. Check for broken piston rings. Replace broken piston rings (TM 9-2815-237-34). END OF TESTING! 15. ENGINE FAILS TO STOP WITH ROTARY SWITCH OFF Check for inoperative fuel shutoff solenoid. Replace inoperative fuel shutoff solenoid (para. 16-8). END OF TESTING! TRANSMISSION NOTE • The transmission is an electronically-controlled four speed. The Transmission Control Module (TCM), an on-board computer, receives and processes input signals from sensors on the vehicle and delivers output signals to the solenoids located on the control valve assembly. These solenoids control the transmission operating pressures, upshift and downshift patterns, and Torque Converter Clutch (TCC) operation. Unit Maintenance has recorded the trouble codes stored in the TCM. Refer to chapter 2 (para. 2-40) for definitions of trouble codes. • In the event of a major transmission malfunction involving the torque converter or oil pump, replace filter and flush oil cooler and lines before replenishing fluid. • Perform the transmission system tests (para. 2-40) and record the readings for use during troubleshooting. • Perform a road test (para. 5-14). • Perform electrical check-out at transmission electrical connector of malfunction 16. 16. TRANSMISSION CONTROL MODULE (TCM) CODES ARE 59, 71, 75, 79, 81, 82, 83 a. Shift solenoid A (1-2) may not function properly (1st and 4th gears only, 2nd and 3rd gears only). Step 1. Disconnect transmission electrical connector. Step 2. Check resistance between pins A and E. Resistance should be between 18 to 24 ohms. Step 3. If resistance at connector is high or low, proceed to step 4. Step 4. Check wires to solenoid for open or short circuit and bad connections. Replace internal harness if damaged (para. 28-3). If ok, proceed to step 5. Table 14-1. Mechanical Troubleshooting (Cont’d).