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| Illustration 1 | g03307257 |
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| Illustration 2 | g01309473 |
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ECM Connectors and Contacts | |
The Implement ECM determines actions that are based on input information and memory information. After the Implement ECM receives the input information, the ECM sends a corresponding response to the outputs. The inputs and outputs of the Implement ECM are connected to the machine harness by two 70 contact connectors (J1 and J2). The ECM sends the information to the AVSpare Electronic Technician (Cat ET) on the Cat Data Link.
Note: The ECM is not serviceable. The ECM must be replaced if the ECM is damaged. Replace the ECM if a failure is diagnosed.
In order to aid in diagnostics of certain types of electrical circuits that are controlled by the ECM, an internal "pull up voltage" is connected to ECM switch and sensor signal input contacts. An above normal voltage is internally connected to the ECM signal input circuit through a resister.
During normal operation, the switch or sensor signal will hold the circuit low or at a certain signal amplitude, however, circuit conditions such as a loss of power to the component, a disconnection, or an open circuit will allow the circuit to be pulled high by the ECM pull up voltage. This condition will result in an above normal voltage condition at the ECM contact. As a result, the ECM will activate an FMI 03 (voltage above normal) diagnostic code for the affected circuit.
The types of ECM input circuits that have pull up voltage present are:
- Pulse Width Modulated (PWM) sensor input circuits
- Switch to Ground Input switch input circuits
- Active analog (voltage) input signal circuits
- Passive analog (resistance) input signal circuits
In order to aid in diagnostics of electrical circuits that are controlled by the ECM, an internal "pull down voltage" is connected to ECM switch to battery type input circuits.
During normal operation, the switch contacts that are allowing the connection to a voltage source will hold the circuit high. When circuit conditions such as a loss of power to the switch supply voltage, a disconnection in the switch circuit or an open circuit will allow the circuit to be pulled low by the ECM pull down voltage. This condition will result in a below normal voltage condition at the ECM contact. As a result, the ECM will activate an FMI 04 (voltage below normal) diagnostic code for the affected circuit.
| Implement ECM Contact Description J1 Contact Descriptions(1) | ||
|---|---|---|
| No.(2) | Type | Function |
| 1 | Key Switch Input | Key Switch On |
| 11 | Sensor Power | +5V Sensor Supply |
| 13 | Battery Return | Battery - |
| 21 | Sensor Power Return | 5V Sensor Return |
| 22 | Analog Input | Hydraulic Oil Temperature Sensor |
| 23 | Battery Return | Battery - |
| 24 | Switch to Battery Input | Implement Shutoff Switch |
| 27 | Switch to Ground Input | ECM Location 1 |
| 31 | Battery Power Input | Battery + |
| 32 | Switch to Ground Input | ECM Location Enable |
| 33 | Switch to Ground Input | Increment Switch (N/C) |
| 34 | Switch to Ground Input | Increment Switch (N/O) |
| 35 | Switch to Ground Input | Decrement Switch (N/C) |
| 36 | Analog Input | Main Implement Pump Pressure Sensor |
| 38 | Battery Power Input | Battery + |
| 39 | Battery Power Input | Battery + |
| 40 | Switch to Ground Input | Decrement Switch (N/O) |
| 41 | Switch to Ground Input | Auto/Manual Switch (N/C) |
| 42 | Switch to Ground Input | Auto/Manual Switch (N/O) |
| 44 | Sensor Power Output | 8V Sensor Power |
| 45 | Sensor Power Return | 8V Sensor Supply |
| 47 | Battery Power Input | Battery + |
| 48 | Sourcing Driver Output | Blade Raise Solenoid |
| 49 | Sourcing Driver Output | Blade Lower Solenoid |
| 50 | Souring Driver Return | PWM Drivers 1 - 4 Return |
| 51 | Sourcing Driver Output | Blade Tilt Left |
| 52 | Sourcing Driver Output | Blade Tilt Right |
| 55 | Souring Driver Return | PWM Driver 9-12 Return |
| 56 | Sensor Power Return | 10V Return |
| 57 | Battery Return | Battery - |
| 58 | Sourcing Driver Output | Ripper Raise / Winch In |
| 59 | Sourcing Driver Output | Ripper Lower / Winch Out |
| 60 | Sourcing Driver Return | PWM Driver 5-8 Return |
| 61 | Sourcing Driver Output | Ripper Shank In / Winch Drum Release |
| 62 | Sourcing Driver Output | Ripper Shank Out / Winch Low Speed Lock |
| 67 | Sourcing Driver Output | Left Tilt Cylinder Extend Solenoid |
| 68 | Sourcing Driver Output | Left Tilt Cylinder Retract Solenoid |
| 69 | Sensory Power Output | 10V Sensor Supply |
| 70 | Battery Return | Battery - |
| (1) | Contacts that are not listed are not used. |
| (2) | The connector contacts that are not listed are not used. |
| Implement ECM Contact Description J2(1) | ||
|---|---|---|
| No.(2) | Type | Function |
| 2 | Sourcing Driver Output | Implement Pilot Supply Solenoid Driver |
| 4 | Sourcing Driver Return | Load Return 1 |
| 22 | Return | Sensor / Driver Return |
| 23 | Switch to Ground Input | Hydraulic Filter Bypass |
| 24 | PWM Input | Blade Raise/Lower Position Sensor |
| 25 | PWM Input | Blade Tilt Position Sensor |
| 26 | PWM Input | Blade Pitch Position Sensor |
| 27 | PWM Input | Ripper Raise/Lower or Drum Clutch Control Position Sensor |
| 32 | PWM Input | Ripper In/Out or Winch In/Out Position Sensor |
| 44 | Switch to Ground Input | Winch Low Speed Lock / Ripper Auto Stow Switch (N/C) |
| 45 | Switch to Ground Input | Winch Low Speed Lock / Ripper Auto Stow Switch (N/O) |
| 46 | Switch to Ground Input | Implement Lockout Switch Enable |
| 47 | Switch to Ground Input | Implement Lockout Switch Disable |
| 50 | PWM Input | 3rd Function Thumb Rocker Switch |
| 54 | Switch to Ground Input | Stable Blade Switch (N/C) |
| 55 | Switch to Ground Input | Stable Blade Switch (N/O) |
| 58 | Switch to Ground Input | Winch Lockout Switch (N/C) |
| 59 | Switch to Ground Input | Winch Lockout Switch (N/O |
| 64 | CAN Data Link + | CAN B Data Link + |
| 65 | CAN Data Link - | CAN B Data Link - |
| 67 | CAN Data Link + | CAN A Data Link + |
| 68 | CAN Data Link - | CAN A Data Link - |
| (1) | The ECM responds to an active input only when all of the necessary conditions are satisfied. |
| (2) | The connector contacts that are not listed are not used. |
The machine has several different types of input devices. The ECM receives machine status information from the input devices and determines the correct output action that is needed in order to control machine operations based on memory and software parameters. The machine utilizes the following types of inputs: switch type and sensor type.
Switches provide signals to the switch inputs of the ECM. The possible outputs of a switch are listed: an open signal, a grounded signal and + battery signal.
Sensors provide an electrical signal to the ECM that constantly changes. The sensor input to the ECM can be one of several different types of electrical signals such as: pulse width modulated (PWM) signals, voltage signals and frequency input signals. Each possible input to the ECM is listed in the tables for the 70-pin connectors.
Inputs provide information to the ECM in the form of sensors or switches.
Sensors provide information to the ECM about the intent of the operator or changing conditions. The sensor signal changes proportionally to the changing of operator input or changing conditions. The following types of sensor signals are used by the ECM.
Frequency - The sensor produces a signal and the frequency (Hz) varies as the condition changes.
Pulse width modulated - The sensor produces a signal. The duty cycle of the signal varies as the condition changes. The frequency of this signal is constant.
Analog - The ECM measures the voltage that is associated to a specific condition of the control.
Hydraulic Oil Temperature Sensor
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| Illustration 3 | g03372390 |
The hydraulic oil temperature sensor is a passive analog sensor. The resistance of the sensor changes proportionally to temperature changes. The ECM measures the resistance of the sensor and determines the temperature of the hydraulic oil. If the ECM detects that the hydraulic oil has exceeded a preset temperature, The ECM sends a signal to the engine ECM to engage the hydraulic fan.
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| Illustration 4 | g03346558 |
The main implement pump sensor is an active analog sensor. The sensor sends an output voltage that is proportional to the pressure of the main implement pump sensor.
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| Illustration 5 | g03719752 |
The ECM receives signals from the blade control handle as pulse width modulated signals. These signals are operator requests for blade movement such as RAISE, LOWER, TILT LEFT, and TILT RIGHT. In most cases, the ECM will respond to the duty cycle of the pulse width modulated signal by sending a corresponding pulse width modulated signal to the related solenoids. The ECM relates a specific sensor duty cycle value to a specific control handle position. The ECM determines the correct solenoid output based on a "software map" that is contained in the programmable memory of the ECM. The ECM receives signals from a position sensor on the X-axis and a position sensor on the Y-axis.
The blade pitch sensor is the proportional thumb rocker located on the blade control handle. The sensor is an active pulse width modulated position sensor. The ECM interprets the pulse width modulated signal as a specific position on the thumb rocker. The thumb rocker controls the blade pitch. A thumb rocker position to the left corresponds with a blade pitch back movement. The ECM sends a corresponding pulse width modulated signal one set of tilt solenoids to cause the blade to pitch forward or back.
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| Illustration 6 | g03376439 |
The ripper control handle has two active pulse width modulated position sensors. One sensor detects ripper raise/lower or spool in/out and one sensor detects ripper shank in/out or drum clutch controls. The ECM interprets the pulse width modulated signals as specific positions on the raise/lower and shank in/out controls. The ECM sends a corresponding pulse width modulated signal to the ripper raise/lower and shank in/out solenoids.
Switches provide an open signal, a ground signal, or a +battery signal to the inputs of the ECM. Switches are open or closed.
- When a switch is open, no signal is provided to the corresponding input of the ECM. This “no signal” condition is also called “floating”.
- When a switch is closed, a ground signal or a +battery signal is provided to the corresponding input of the ECM.
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| Illustration 7 | g03346014 |
The implement shutoff switch is a two pole switch. The switch has a normally connected and a normally open contact. When the switch is not depressed the normally connected contact is connected to the return, and the normally open contact floats to a high voltage state. When the switch is depressed, the normally open contact is connected to the return and the normally connected contact floats to a high voltage state. Based on the voltage state of the two ECM contacts, the ECM determines if the switch is depressed. The second pole on the switch allows the path of power from an ECM driver to flow through the switch to the shutoff solenoid.
Increment and Decrement Switch
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| Illustration 8 | g03719752 |
The increment and decrement switches are single pole switches. Both switches have a normally connected and a normally open contact. When the switch is not depressed the normally connected contact is connected to the return, and the normally open contact floats to a high voltage state. When the button is depressed, the normally open contact is connected to the return and the normally connected contact floats to a high voltage state. Based on the voltage state of the two ECM contacts, the ECM determines if either of the buttons are depressed. The buttons control the increment and decrement blade height function.
Ripper Autostow / Winch Low Speed Lock Switch
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| Illustration 9 | g03376439 |
The ripper autostow switch is a single pole switch. The switch has a normally connected and a normally open contact. When the pushbutton on the ripper handle is not depressed, the normally connected contact is connected to the return and the normally open contact floats to a high voltage state. When the pushbutton is depressed, the normally open contact is connected to the return and the normally connected contact floats to a high voltage state. Based on the voltage state of the two ECM contacts, the ECM determines if the autostow switch pushbutton has been depressed. The button engages the autostow feature for the ripper.
Hydraulic Oil Tank Filter Bypass Switch
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| Illustration 10 | g03348326 |
The hydraulic oil tank filter bypass switch is a single pole pressure switch. When the switch is closed under normal operation, the ECM contact is connected to a return contact. When the hydraulic pressure exceeds a set point, the switch opens. When the switch opens, the ECM contact floats to a high voltage from the ECM pull-up voltage. When the switch opens, the ECM alerts the operator that the hydraulic oil tank filter is being bypassed.
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| Illustration 11 | g03720912 |
The stable grade switch is a two pole switch with a normally connected and normally open contact. The ECM monitors the voltage state of the two contacts, and determines if the stable grade switch has been activated.
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| Illustration 12 | g03720928 |
The winch lockout switch is a two pole switch with a normally connected and normally open contact. The ECM monitors the voltage state of the two contacts, and determines if the winch lockout switch has been activated.
The ECM responds to decisions by sending electrical signals to the outputs. The outputs can create an action or the outputs can provide information to the operator or the service technician.
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| Illustration 13 | g03720746 |
All proportional solenoids in the implement system are identical in construction, however function differently. Illustration 13 shows an example of a proportional solenoid in the implement system.
Note: The solenoid coils are not designed to operate using 24 DCV directly. The ECM sends a PWM signal of 24 V at a duty cycle that will provide the necessary current to the solenoid coils. Do NOT activate the coils by using 24 DCV (+battery). The life of the coils will be reduced drastically. A source of 12 DCV should be used, if the coils must be activated by not using the ECM.
There are two solenoids controlling blade height. There is one blade raise solenoids and one blade lower solenoids. The two solenoids are identical in construction, and control the operation of the blade height valve spool. The solenoids are proportional solenoids, and if the ECM sends a higher duty cycle signal to the blade raise solenoid, that solenoid shifts the spool further in the direction of the RAISE position. If the ECM sends a higher duty cycle signal to the blade lower solenoid, that solenoid shifts the spool further in the direction of the LOWER position. The raise and two lower solenoids are linked and the ECM will send signals to both solenoids to provide a smooth spool movement.
There are four solenoids controlling blade tilt. There is a left extend and retract tilt, and right extend and retract solenoid. The solenoids are identical in construction, and each set controls the operation of a blade tilt valve spool. The solenoids are proportional solenoids and depending on the duty cycle of the ECM outputs the left and right tilt spools will shift depending upon input. The tilt spools may act simultaneously in dual tilt mode, or independently in single tilt mode.
There are two solenoids controlling ripper height. There is a ripper raise and lower solenoid. The two solenoids are identical in construction, and together control the operation of the ripper raise/lower spool. The solenoids are proportional solenoids, and if the ECM sends a higher duty cycle signal to the ripper raise solenoid, that solenoid shifts the spool further in the RAISE position. If the ECM sends a higher duty cycle signal to the ripper lower solenoid, that solenoid shifts the spool further in the LOWER position. The two solenoids operate together to control the movement of the ripper raise/lower spool.
There are two solenoids controlling ripper shank movement. There is a ripper shank in and out solenoid. The two solenoids are identical in construction, and together control the operation of the ripper shank in/out spool. The solenoids are proportional solenoids, and if the ECM sends a higher duty cycle signal to the ripper shank in solenoid, that solenoid shifts the spool further in the SHANK IN position. If the ECM sends a higher duty cycle signal to the ripper shank out solenoid, that solenoid shifts the spool further in the SHANK OUT position. The two solenoids operate together to control the movement of the ripper shank in/out spool.
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| Illustration 14 | g03349477 |
The ripper pin puller solenoid is an on/off solenoid. The solenoid is directly activated by a switch in the cab. The solenoid controls the movement of the pin that locks a ripper tooth in place.
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| Illustration 15 | g03422260 |
The implement shutoff solenoid is activated by the implement shutoff switch. When the switch is activated, a circuit is completed allowing energy to flow to the implement lockout solenoid. The solenoid is an on/off type solenoid. When the solenoid is activated, the solenoid prevents the implement system from operating.
Electronic communication between the Implement ECM, Power train ECM, Engine ECM, and the other control modules on the machine is conducted over data link circuits. The data link circuits allow the sharing of information with other electronic control modules. The data link circuits are bidirectional. The data link circuit allows the ECM to send information and to receive information.
The electronic communication system consists of multiple CAN datalink systems.
The SAE J1939 CAN Data Link circuit is separated into different groups. "CAN A" is connected to all of the ECMs on the machine, and is used primarily for information and service purposes, such as the AVSpare Electronic Technician (AVS ET). The other data link systems are high speed data links used for machine control purposes.