| |
| Illustration 1 | g06246078 |
|
ECM Inputs (1) Fuel Level Sensor (2) Left Rear Leg Cylinder Position Sensor (3) Left Front Leg Cylinder Position Sensor (4) Right Rear Leg Cylinder Position Sensor (5) Right Front Leg Cylinder Position Sensor (6) E-Stop 1 Switch (7) E-Stop 2 Switch (8) E-Stop 3 Switch (9) E-Stop 4 Switch (10) Horn Switch 1 (Rear Left) (11) Horn Switch 2 (Front Left) (12) Horn Switch 3 (Front Right) (13) Horn Switch 4 (Rear Right) (14) Conveyor Swing Manual Release Valve Switch (15) Hydraulic Oil Filter Differential Pressure Switch (16) Hydraulic Oil Level Switch (17) Hydraulic Oil Temperature Sensor (18) Rotor Speed Sensor (19) Water Pressure Sensor (20) Right Side Plate Front Cylinder Sensor (21) Right Side Plate Rear Cylinder Sensor (22) Drive Circuit #1 Pressure Sensor (23) Drive Circuit #2 Pressure Sensor (24) Brake Pressure Sensor (25) Right Front Speed Sensor (26) Left Front Speed Sensor (27) Right Rear Speed Sensor (28) Left Rear Speed Sensor (29) Front Tie Rod Cylinder Sensor (30) Rear Tie Rod Cylinder Sensor (31) Front Steering Cylinder Sensor (32) Rear Steering Cylinder Sensor (33) Left Grade Control Ski Position Sensor (34) Right Grade Control Ski Position Sensor (35) Left Side Plate Front Cylinder Position Sensor (36) Left Side Plate Rear Cylinder Position Sensor (37) Water Tank Level Sensor (38) Moldboard Lowered Position Switch (39) Moldboard Raised Position Switch | |
The electronic control system utilizes various different types of devices that provide input data to the Electronic Control Modules (ECM). Each ECM receives data about the status of the machine from the input devices. The ECM will use the status information to determine the correct output action that is needed. The output action is based on the memory and software parameters. The output action controls the various functions of the machine. All the components that supply inputs to each ECM fall into one of the following groups:
- Switch inputs
- Sensor inputs
Switches provide signals to the switch inputs of the ECM. The possible outputs of a switch are an open signal, a grounded signal, or a voltage signal.
Sensors provide an electrical signal to the ECM that constantly changes. The sensor input can be one of the following types of signals:
- Pulse Width Modulated (PWM) signal
- Active analog (voltage) signal
- Passive analog signal
- Frequency
The ECM monitors most of the circuits of the input components for diagnostics. If the ECM determines that an abnormal condition exists, a diagnostic code will be logged for the component involved.
Most input circuits of the sensors have an internal ECM "pull up voltage" that is present at the contacts of the ECM. An above normal voltage is internally connected to the input circuit of the ECM through a resistor. During normal operation, the sensor signal will hold the circuit at a certain amplitude. Specific circuit conditions will allow the circuit to be pulled high by the pull-up voltage of the ECM. These conditions include a loss of power to the component, a disconnection of the circuit, or an open circuit. Such a condition will result in an above normal voltage at the contact of the ECM. This above normal voltage causes the ECM to activate an FMI 03 diagnostic code for the circuit that is affected. The FMI 03 diagnostic code indicates a voltage that is above normal.
A pull-up voltage is present in the following types of circuits:
- PWM
- Active analog (voltage)
- Passive analog (resistance)
| |
| Illustration 2 | g03350145 |
|
Fuel Level Sensor | |
The fuel level sensor is an active analog sensor. The electronics of the sensor measures the change in capacitance of the tube wall as the fluid height on the tube changes. This measurement is then converted by the sensor into an analog voltage signal for the Machine ECM to read. The Machine ECM monitors the analog voltage signal of the sensor signal at Machine ECM connector contact J1-36
| Fuel Level Sensor Output | |
| Percent of Fuel in Tank | Sensor Output Voltage |
| 0% (Empty) | 0.5 V |
| 25% | 1.5 V |
| 50% | 2.5 V |
| 75% | 3.5 V |
| 100% (Full) | 4.5 V |
The Leg Cylinder Position Sensors send PWM information to the Machine ECM on the following pins:
- Left Rear - J1-15
- Left Front - J1-16
- Right Rear - J1-17
- Right Front - J1-18
| Leg Cylinder Position Sensors | |
| Displacement | Cylinder Position Sensor PWM (%) |
| 0.0 (Fully Retracted) | 10.00 |
| 369.0 (Scratch) | 51.58 |
| 419.0 (Pre-Scratch) | 57.21 |
| 658.0 (Pre-Service) | 84.14 |
| 708.0 (Fully Extended) | 89.77 |
Hydraulic Oil Temperature Sensor (17)
The Hydraulic Oil Temperature Sensor sends a signal to the Transmission ECM pin J1-22.
The Rotor Speed sensor sends a signal to the Transmission ECM pin J1-18.
The Water Pressure Sensor sends a signal to the Transmission ECM pin J1-36.
Right Side Plate Front (20), Right Side Plate Rear (21) Cylinder Sensors
These Cylinder Sensors send signals to the Transmission ECM. Right Side Plate Front to pin J2-40, Right Side Plate Rear to pin J2-41.
Drive Circuit #1 (22), Drive Circuit #2 (23) Pressure Sensors
The Drive Circuit Pressure sensors are connected to the Transmission ECM at pin J2-48 for #1 and pin J2-49 for #2.
The Brake Pressure Sensor sends a signal to the Transmission ECM pin J2-32.
Right Front (25), Left Front (26), Right Rear (27), Left Rear (28) Speed Sensors
These Speed Sensors each send dual signals to the Transmission ECM at the following connections:
- Right Front - Pins J2-15, 16
- Left Front - Pins J2-17, 18
- Right Rear - Pins J2-24, 25
- Left Rear - Pins J2-26, 27
Front Tie Rod (29), Rear Tie Rod (30) Cylinder Sensors
These Cylinder Sensors send signals to the Steering ECM at pin J2-16 for the Front Tie Rod and to pin J2-18 for the Rear Tie Rod.
Front Steering (31), Rear Steering (32) Cylinder Sensors
These Cylinder Sensors send signals to the Steering ECM at pin J2-15 for the Front Tie Rod and to pin J2-17 for the Rear Tie Rod.
Left (33), Right (34) Grade Control Ski Position Sensors
These Grade Control Ski Position Sensors send signals to the Steering ECM. Left sensor to Pin J2-59 and Right sensor to Pin J2-58.
Left Side Plate Front (35), Left Side Plate Rear (36) Cylinder Position Sensors
These Cylinder Position Sensors send signals to the Steering ECM. Left Side Plate Front sensor to Pin J2-40 and Left Side Plate Rear to Pin J2-41.
The Water Tank Level Sensor sends a signal to the Steering ECM pin J1–37. Pin J2-37 will be grounded to Frame Ground to indicate the sensor is installed. If J2-37 is Open, the sensor is Not Installed.
Switches will provide one of the following types of input signals to the ECM:
- An open signal
- A ground signal
- A +battery or voltage signal
The contacts of a switch have two states of contact. The switch contacts are open or the switch contacts are closed.
- When switch contacts are open, no signal is provided to the corresponding input of the ECM. The "no signal" condition is also referred to as floating.
- When switch contacts are closed, a ground signal or the +battery signal passes through the contacts of the switch. The signal is also passed to the corresponding input of the ECM.
Switch to ground type input circuits have an internal ECM pull-up voltage. The voltage is present at the contacts of the ECM. An above normal voltage is internally connected to the input circuit of the ECM through a resistor. This voltage allows the ECM to detect a problem in the switch circuit. During normal operation, the switch signal will maintain a low level in the circuit. However, circuit conditions such as a disconnection or an open circuit will allow the circuit to be pulled high by the ECM pull-up voltage. The presence of the pull-up voltage will result in an above normal voltage at the contact of the ECM. The ECM will activate a diagnostic code when a low voltage is expected, but a high voltage is present.
Switch to +battery type input circuits have an internal ECM pull-down voltage. The voltage is present at the contacts of the ECM. A below normal voltage is internally connected to the input circuit of the ECM through a resistor. The pull-down voltage allows the ECM to detect a problem in the switch circuit. The circuit will be held high when the switch contacts are closed to a +battery source. If the circuit is an open or if the circuit has a bad connection, the pull-down voltage will pull the circuit low. The ECM will activate a diagnostic code when a high voltage is expected, but a low voltage is present.
The ECM monitors the input circuits for most of the following switches: The ECM will activate a diagnostic code for the input circuits of the switch when an abnormal condition is detected.
E-Stop 1 (6), E-Stop 2 (7), E-Stop 3 (8), E-Stop 4 (9) Switches
- E-Stop 1 - Lower Left Front
- E-Stop 2 - Lower Right Front
- E-Stop 3 - Lower Left Rear
- E-Stop 4 - Lower Right Rear
Horn 1 (10), Horn 2 (11), Horn 3 (12), Horn 4 (13) Switches
- Horn 1 - Rear Left
- Horn 2 - Front Left
- Horn 3 - Front Right
- Horn 4 - Rear Right
Conveyor Swing Manual Release Valve Switch (14)
The Conveyor Swing Manual Release Valve Switch signal connects to Machine ECM pins J2-28 and J2-29.
Hydraulic Oil Filter Differential Pressure Switch (15)
The Hydraulic Oil Filter Differential Pressure Switch signal connects to Transmission ECM Pin J1-40.
Hydraulic Oil Level Switch (16)
The Hydraulic Oil Level Switch signal connects to Transmission ECM Pin J1-35.
Moldboard Lowered (38), Moldboard Raised (39) Position Switches
The Moldboard Position Switches send signals to the Steering ECM at Pin J1-42 for the Lowered Position and Pin J1-41 for the Raised Position.