Solenoids
Solenoid Valve (Charge)
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| Illustration 1 | g00800902 |
Solenoid valve for charge pressure | |
The charge solenoid directs oil from the AWD pump to the drive motors. The solenoid is activated by a continuous signal that is sent by the all wheel drive ECM. The solenoid has a resistance of 32.6 Ohms ± 1.6 Ohms at a temperature of 25° ± 5°C (77° ± 9°F).
Note: The charge solenoid is always activated before the drive solenoid. Therefore, the drive motors fill with charge oil before the high pressure oil arrives for turning the front wheels.
The ECM monitors the solenoid for the following problems: a short to + battery, a short to ground and a open circuit. A diagnostic code will be set and the AWD mode will be disabled.
Solenoid Valve (Drive) (Freewheel)
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| Illustration 2 | g00800902 |
Solenoid valve for drive motors | |
The drive solenoid valve directs high pressure oil from the AWD pump to the drive motors. The solenoid is activated by a continuous signal that is sent by the all wheel drive ECM. The solenoid has a resistance of 32.6 Ohms ± 1.6 Ohms at a temperature of 25° ± 5°C (77° ± 9°F).
During AWD operation, the ECM normally energizes the drive solenoid. High pressure oil is then directed to the drive motors for turning the front wheels of the machine. At this time, the forward pump line is connected to the forward drive motor line. The reverse pump line is connected to the reverse drive motor line. The forward and reverse lines are NOT connected together.
The solenoid valve is energized when the AWD mode is active and the transmission is operating in eighth gear (forward) or sixth gear (reverse).
The ECM monitors the solenoid for the following problems: a short to + battery, a short to ground and a open circuit. A diagnostic code will be set and the AWD mode will be disabled.
Solenoid Valve (Motor Displacement)
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| Illustration 3 | g00800902 |
Solenoid valve for motor displacement | |
The motor displacement solenoid valve controls the pilot oil signal that changes the displacement of the drive motors. The drive motors are dual displacements:small and large. The solenoid is activated by a continuous signal that is sent by the ECM. The solenoid has a resistance of 32.6 Ohms ± 1.6 Ohms at a temperature of 25° ± 5°C (77° ± 9°F).
The ECM will energize the motor displacement solenoid valve when the AWD mode is active and the transmission is operating in one of the following gears:
- Fifth gear (forward)
- Sixth gear (forward)
- Seventh gear (forward)
- Eighth gear (forward)
- Fourth gear (reverse)
- Fifth gear (reverse)
- Sixth gear (reverse)
Note: The AWD ECM receives the selected transmission gear from the transmission ECM over the CAT data link.
The ECM monitors the solenoid for the following problems: a short to + battery, a short to ground and a open circuit. A diagnostic code will be set and the AWD mode will be disabled.
Solenoid Valve (Pump Pressure)
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| Illustration 4 | g00800908 |
Solenoid valve for pump pressure | |
The solenoid valve directs oil flow to the pressure sensor for the drive pressure of the all wheel drive piston pump. The solenoid has a resistance of 32.6 Ohms ± 1.6 Ohms at a temperature of 25° ± 5°C (77° ± 9°F).
The ECM monitors the solenoid for the following problems: a short to + battery, a short to ground and a open circuit. A diagnostic code will be set and the AWD mode will be disabled.
Solenoid Valve (Pump Displacement) For Forward Operation and Reverse Operation
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| Illustration 5 | g00800957 |
Solenoid valve for the pump displacement for forward operation and for reverse operation | |
The solenoid valve controls the swashplate of the AWD pump. The solenoids are proportional solenoids. The ECM uses a pulse width modulated signal (PWM) in order to vary the current to the solenoids. The distance of the solenoid plunger is in proportion to the signal that is sent by the ECM. The position of the solenoid plunger controls the angle of the swashplate within the AWD pump. The output of the AWD pump will become greater as the angle of the swashplate becomes greater. The solenoids have a resistance of 25 Ohms.
When the transmission is in a FORWARD gear, the ECM activates the solenoid valve for the forward pump displacement. When the transmission is in a REVERSE gear, the ECM activates the solenoid valve for the reverse pump displacement. The ECM calculates the required pump pressure and the ECM uses the solenoid in order to maintain the calculated value.
The ECM monitors the solenoid for the following problems: a short to + battery, a short to ground and a open circuit. A diagnostic code will be set and the AWD mode will be disabled.
Indicators
Indicator Lamp (All Wheel Drive) (AWD)
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| Illustration 6 | g00922181 |
Indicator lamp for the all wheel drive system | |
The all wheel drive ECM activates the all wheel drive lamp. The lamp will be illuminated when the all wheel drive system is active.
The indicator is a clear lamp that is rated for 24 volts.
The ECM monitors the indicator lamp for the following problems: a short to + battery, a short to ground and a open circuit. A diagnostic code will be set.