- The secondary steering solenoid valves are activated.
- The secondary steering pump is activated.
- The secondary steering pump is activated and the secondary steering solenoid valves are activated.
The secondary steering system has the following main components:
- Secondary steering pump and motor
- Hydraulic tank and filter
- Pilot control manifold
- Steering control valve
- Transmission/chassis electronic control module (ECM)
- Magnetic switch (Secondary Steering Motor Relay)
Secondary Steering Pump and Motor
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| Illustration 1 | g03590636 |
| (2) secondary steering motor | |
The secondary steering pump and motor are located in the front of the rear frame near the articulated hitch. The secondary steering pump is gear pump driven by an electric motor. The gear pump provides oil flow to the pilot control manifold.
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| Illustration 2 | g03590783 |
The steering control valve is located on the front frame in front of the cab. the steering control valve contains the secondary pressure reducing valve and the secondary steering solenoid valves.
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| Illustration 3 | g03590779 |
The transmission/chassis ECM is mounted to the back side of the transmission and acts as the central processing unit for the secondary steering system.
Magnetic Switch (Secondary Steering Motor Relay)
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| Illustration 4 | g03590736 |
Magnetic switch (secondary steering motor relay) is located in the front of the rear frame near the articulated hitch.
The secondary steering system will activate the secondary steering pump or the secondary steering system will activate the secondary steering solenoid valves under various conditions. The secondary steering pump is activated in automatic mode under the following conditions:
- The main hydraulic pump has failed.
- There is zero engine speed while the machine is moving with ground speed.
The secondary steering system will activate the secondary steering solenoid valves under the following conditions:
- An error code is received for the controller for the primary steering control valve.
- A steering signal is detected with no input by the operator.
- A steering signal is not detected with an input signal from the operator.
- A steering signal is detected in the wrong direction from the operator input.
The transmission/chassis electronic control module (ECM) will only turn on the parts of the secondary steering system that are required for machine operation. If the primary steering system solenoids are not functioning properly, only the secondary steering solenoid valves will be activated. If the main hydraulic pump for the steering fails, only the secondary steering pump will be activated. Both the secondary steering pump and the secondary steering solenoid valves can be activated at the same time if both conditions apply.
The secondary steering pump provides hydraulic oil to the steering system in the event of pressure loss in the primary steering system.
The secondary steering motor is powered by the battery. The secondary steering motor will only run for a short time before the battery power has been depleted. Extended use of the secondary steering pump will damage the secondary steering pump. Secondary steering will be used in the event of an engine failure that results in zero engine speed. The machine must be in motion in order to use the secondary steering pump.
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| Illustration 5 | g03590518 |
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Secondary steering function (1) Implement ECM 2 (2) Left-hand Joystick Connector 1 (3) Left-hand Joystick Connector 3 (4) Transmission/Chassis ECM (5) Left-hand Steering Cylinder (6) Right-hand Steering Cylinder (7) Redundant Pilot Pressure port (8) Redundant Pressure Reducing Valve (9) Right-hand Secondary Steering Solenoid (10) Steering Crossover Relief Valve (11) Steering Crossover Relief Valve (12) Right-hand Primary Steering Solenoid (13) Primary Pilot Steering Solenoid (14) Pilot Supply Port (15) Pilot Drain Port (16) Left-hand Secondary Steering Solenoid (17) Spool Position Sensor (18) Directional Spool (19) Left-hand Primary Steering Solenoid (20) Implement Supply Port (21) Priority Valve (22) Pump Supply Port (23) Load Sense Port (24) Relief Valve (25) Tank Port | |