TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download
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TM 9-2320-280-20-1 REFERENCE INFORMATION TRANSMISSION SYSTEM (4L80-E) DTC 39 TCC Stuck “OFF” Circuit Description: The TCM commands the TCC PWM solenoid “ON” by modulating TCC signal fluid acting on the converter clutch shift valve. Then TCC fluid applies the torque converter clutch. DTC 39 Will Set When: ● TCC is commanded “ON.” ● TCC slip speed greater than 65 RPM. ● Trans range in D3 or D4. ● 2nd or 3rd gear. ● All conditions are met for two seconds. DTC 51 Faulty or Incorrect Circuit description: 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. DTC 51 Will Set When: ● There is an uncorrectable computational error, or an input is in error intermittently. DTC 52/53 System Voltage High Long/ System Voltage High Circuit Description: Ignition voltage is supplied to the control module to indicate the status of the ignition switch. Battery voltage is supplied to the control module to, in part, maintain memory of learned functions and parameters. DTC 52 Will Set When: ● The ignition is “ON” and the system voltage is greater than 16 volts. ● Condition is met for 109 minutes. DTC 53 Will Set When: ● The ignition is “ON” and the system voltage is greater than 19.5 volts. ● Condition is met for 2 minutes. DTC 58 Transmission Fluid Temperature (TFT) Sensor Circuit Low (High Temperature Indicated) Circuit Description: The TFT sensor is a thermistor that controls the signal voltage to the TCM, The TCM supplies a 5-volt reference signal to the sensor on TWC pin “L.” When the transmission fluid is cold, the sensor resistance is high and the TCM will sense high signal voltage. As the transmission fluid temperature warms to normal transmission operating temperature 212°F (100°C), the sensor resistance becomes less and the voltage decreases to approximately 1.5 to 2.0 volts. With DTC 79 also set, check the transmission cooling system. DTC 58 Will Set When: ● Signal voltage indicates TFT greater than 304°F (151°C). ● Condition is met for 1 second. 2-423