Normal Operation
The Machine ECM receives the operator's requested speed and direction for the machine from the "FNR" Shift Handle - Autoshift over the Cat Data Link for 420E and 430E BHL machines. The "FNR" Shift Handle for the 414E and the 416E backhoe loader uses switch inputs to control the transmission.
The control module will direct the operation of the transmission's solenoids when the following prerequisites are established. The shift lever is communicating to the control module and the control module has received the gear information.
The actions of the Machine ECM are based on the status of the following components:
- "Auto/Manual" switch
- "Neutral Lock" switch
- Shift lever control module - "FNR" Autoshift
- "Neutralizer/Downshift" switch
- "Parking Brake" switch
- "Ride Control" switch
The "Autoshift" transmission is controlled by a twist handle. The handle is located on the control for the shift lever. The "Autoshift" twist handle has four positions.
High Speed Directional Shift
No precaution is taken when the machine's direction is shifted by the Autoshift transmission control. If you shift from the fifth gear forward to the third gear reverse, the transmission will shift to third gear reverse.
Power Up
When the Machine ECM is energized, the transmission is placed in neutral. This is done regardless of the shift lever's position. Prior to travel, the shift lever must pass through the NEUTRAL position. The transmission will remain in neutral until this has been accomplished.
Neutral Start
The signal for the start relay goes through the shift lever. The shift lever must be in the NEUTRAL position in order to allow cranking of the engine. The lever must pass through the NEUTRAL position before a direction can be selected.
Modes of Operation
The "FNR" Shift Handle - Autoshift has an automatic shift function and a manual shift function.
Ride Control
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| Illustration 1 | g01654154 |
Ride control circuit | |
Ride Control Switch: This switch provides two inputs to the Machine ECM.
- "Ride control automatic operation"
- "Ride control ON"
- "Ride control OFF"
A three-position switch controls the ride control function. In the held middle OFF position, the ride control function is disabled. In the ON position, the ride control solenoid is always enabled. In the held AUTO position, the ride control function activates the ride control solenoid valve when the ground speed is greater than a set limit. The ride control solenoid valve is deactivated when the machine ground speed is at least 1 km/h less than the set speed limit. The default set limit for the AUTO position is 9 km/h. AVSpare Electronic Technician (ET) will be used to change the set limit. For the purpose of calculating ground speed, a nominal tire radius of 635 mm (25 inch) shall be used. A pressure switch is placed in series with the ride control relay that controls the solenoid. When there is pressure on the rod end of the lift cylinder, the circuit of the solenoid driver is open. The ride control function will be prevented from being engaged when there is a load on the rod end, such as when the loader is being used as a stabilizer. Use of a relay driver also prevents diagnostics from being performed on the "ride control" solenoid circuit.
Note: Whenever the ride control solenoid is activated, the loader lock bypass solenoid (if installed) must also be activated so that lift arm motion can occur. Ride control on the 414E and the 416E mechanical machines is switched ON or switched OFF by electrical means only. These machines are not offered with both Ride Control and Loader Lock valves. Switches on these machines have no AUTO position, and both ON & OFF positions are held.
Ride Control Disable: A pressure switch within the rod end of the lift cylinder is used in order to sense when the loader is applying a downward force. The switch deactivates at 3137 ± 175 kPa (455 ± 25.4 psi). The control module will disable the ride control function by de-energizing the ride control relay.
Ride Control Enable: A pressure switch within the rod end of the lift cylinder is used to sense when the loader is administering a downward force. The switch is activated at a maximum pressure of 3500 kPa (508 psi). The control module will enable the ride control function by energizing the ride control relay. The ride control enable input is activated by the operator and sent to the Machine ECM. The ride control will be enabled when this input has +battery voltage.
MSS Key Reader Control
The Machine Security System (MSS) provides security protection to the machine. If the MSS LED indicator is red, the engine will not start. Before a key can operate the machine, the MSS must be set to accept that particular key. Once the Machine Security System (MSS) has granted access for the key the red LED will turn OFF.
The MSS uses the AVSpare Electronic Key. The AVSpare Electronic Key contains a transponder that is embedded in the head of the key. The electronic chip has a unique identification number (ID). An exciter coil is mounted around the key start switch. The exciter coil reads the ID of the key.
The Electronic Control Module (ECM) of the Machine Security System is setup with the ID of the keys of the intended users. When the MSS is armed, the ECM validates the ID of the key in the key start switch. If the ID for the key is in the list of authorized keys in the ECM and the key is valid, the machine will operate normally. If the ID for the key is not in the list of authorized keys in the ECM or the key is not valid in the ECM, the MSS will keep the critical machine functions disabled.
Note: Ensure that you have only one electronic key near the exciter coil when the MSS reads the key. If there is more than one key the ECM will not be able to read the key and the machine will not start.
Automatic Engine Speed Control
The "Automatic Engine Speed Control (AESC)" feature can be turned ON or OFF by using a switch that is located on the console. The console for the switch is located to the right side of the operator when the operator is facing the loader of the machine. The logic for the software resides on the Machine ECM. Some of the inputs for the AESC are routed through the Engine ECM. The purpose of the AESC is to command the Engine ECM to reduce the speed of the engine after a specific amount of time when no hydraulic command is present. The "AESC" function operates only when the seat position of the operator is facing the hoe bucket of the machine and the "AESC" function is enabled.
The "Manual Low Idle" button will be active regardless of the position of the AESC switch and the operator seat is in the position that is facing the hoe bucket.
Parking Brake
The parking brake uses the following components:
- Machine Electronic Control Module
- Parking Brake Switch
- In−Gear Relay
- Parking Brake Indicator
The parking brake switch alerts the Machine ECM of the status of the parking brake. The brake can be applied or the brake can be released.
The machine will remain in neutral under the following conditions:
- The parking brake is applied and the machine is placed in gear.
- The machine is in gear and the parking brake is applied.
The shift lever must be shifted back to the NEUTRAL position and the parking brake released in order to resume normal operation.
The Drive Through Operation of the Parking Brake:
1 - The parking brake is applied and the shift lever is in the NEUTRAL position. The operator is facing the loader (front of machine) in order to drive the machine with the parking brake applied.
2 - Shift the machine into gear.
3 - Shift the machine back into the NEUTRAL position.
4 - Within 3 seconds, shift the machine back into gear.
The machine will be in gear and an audible alarm will be active. A parking brake abuse event will be logged in the machine control module if the speed of the vehicle exceeds 1 mile per hour. Releasing the parking brake will silence the alarm. This leaves the machine in normal operation. The alarm is also silenced when the machine is in NEUTRAL.
Transmission Auto/Manual Switch
The Transmission auto/manual switch supplies two switch to ground inputs. The inputs are used in order to select the automatic shift function or the manual shift function of the "FNR" Shift Handle - Autoshift. The switch has diagnostic capabilities.
When auto/manual input "auto" is to ground and auto/manual input "man" is open, the automatic mode is selected. When auto/manual input "auto" is open and auto/manual input "man" is to ground, the manual mode is selected.
If the inputs are identical (both open or both ground) for a minimum of five seconds, a diagnostic fault is logged. The machine will default to the manual shift function. When the Auto/Manual switch is used, the shift lever does not need to first pass through the NEUTRAL position to make the switch from AUTO to MANUAL or from MANUAL to AUTO.
Neutral Lock
When the neutral lock switch is depressed, the feature holds the machine in neutral. The switch signals the transmission control to ignore shift lever's position. Depressing the switch signals the control module to ignore the shift lever. All of the transmission solenoids remain inactive. This holds the machine in neutral.
The machine's neutral lock uses the following components:
- Machine Electronic Control Module
- Neutral Lock Switch
If the neutral lock switch is depressed and the machine is in gear, the control module will immediately shift the machine into neutral. The transmission will remain in neutral until the shift lever is returned to the NEUTRAL position and the neutral lock is turned off.
When the neutral lock switch is closed to ground the transmission is placed in neutral regardless of the state of the shift lever. The transmission remains in neutral until the neutral lock switch is opened and the shift lever is placed in neutral. This must happen before the machine is placed in gear.