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| Illustration 1 | g01152734 |
Travel speed control for machines in the following serial number ranges: BDR1-2000, BDM1-2000, BDX1-2000, BCZ1-2000, BDK1-2000, BDY1-2000 and BEB1-2000. | |
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| Illustration 2 | g01152735 |
Travel speed circuit connections for machines in the following serial number ranges: BDR1-2000, BDM1-2000, BDX1-2000, BCZ1-2000, BDK1-2000, BDY1-2000 and BEB1-2000. | |
The ECM will allow the operator to select one of two travel speeds. The two travel speeds are high and low. The availability of two travel speeds offers the operator greater control of the machine. In order for the ECM to enable the travel speed function, the left armrest must be down.
The signal for low speed or high speed is sent from the travel speed switch on the soft switch panel (SSP) to the ECM on the CAN data link.
When the selected speed is low, the ECM will energize the travel speed solenoid. When the selected travel speed is high, the ECM will de-energize the travel speed solenoid.
Activation Of The Travel Speed Solenoid
The travel pedal is mechanically connected to the travel pilot pressure system. When the travel pedal is pressed in either the forward or the rearward direction, travel pilot pressure is enabled. The travel speed will default to high speed. In order to select the low speed, the ECM will determine that the following conditions are correct.
- The low travel speed is requested by the operator.
- The parking brake is off.
- The left console is down.
If these conditions are not correct, the ECM will de- energize the travel speed solenoid in order to default to the high speed.
The travel speed solenoid will be deactivated when the parking brake is engaged. After the parking brake is disengaged, the machine will return to the previous travel speed.
Note: If the limp home mode is activated, the travel speed will be low.
Activation Of The Gear Shift Solenoids
Note: The following text and illustrations details travel speed control for machines in the in S/N ranges BDR2001-UP, BDM2001-UP, BDX2001-UP, BCZ2001-UP, BDK2001-UP, BDY2001-UP, BEB2001-UP, H2A1-UP, H2B1-UP, H2C1-UP, H2D1-UP, H2E1-UP, H2F1-UP and H2G1-UP.
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| Illustration 3 | g01152749 |
Travel speed control for machines in the following serial number ranges: BDR2001-UP, BDM2001-UP, BDX2001-UP, BCZ2001-UP, BDK2001-UP, BDY2001-UP, BEB2001-UP, H2A1-UP, H2B1-UP, H2C1-UP, H2D1-UP, H2E1-UP, H2F1-UP and H2G1-UP. | |
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| Illustration 4 | g01152750 |
Travel speed circuit connections for machines in the following serial number ranges: BDR2001-UP, BDM2001-UP, BDX2001-UP, BCZ2001-UP, BDK2001-UP, BDY2001-UP, BEB2001-UP, H2A1-UP, H2B1-UP, H2C1-UP, H2D1-UP, H2E1-UP, H2F1-UP and H2G1-UP. | |
The ECM will allow the operator to select between a high travel speed or low travel speed. The travel speed is selected from the travel speed switch on the SSP. The switch status is supplied to the ECM over the Can data link. The default travel speed is the high speed. In order for the ECM to enable the low travel speed, the following conditions must be correct.
- The low travel speed is requested by the operator.
- The parking brake is off.
- The left console is down.
The travel pedal is mechanically connected to the travel pilot pressure system. When the travel pedal is pressed in either the forward or the rearward direction, travel pilot pressure is enabled. When the listed conditions are correct, the ECM will energize transmission gear shift solenoid 1 in order to set the transmission to low speed. When the default high speed is selected and active, the ECM will energize transmission gear shift solenoid 2. If both solenoids are activated at the same time, a diagnostic code will activate. The Monitor will display a "POWERTRAIN ERROR" message and machine travel will be disabled.
Reference: For more information on the travel pedal operation and travel motor control, refer to Systems Operation, "Travel Activation Function"
Travel Motor Control
Note: This information applies to machines in the following serial number ranges: BDR2001-UP, BDM2001-UP, BDX2001-UP, BCZ2001-UP, BDK2001-UP, BDY2001-UP, BEB2001-UP, H2A1-UP, H2B1-UP, H2C1-UP, H2D1-UP, H2E1-UP, H2F1-UP and H2G1-UP
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| Illustration 5 | g01152762 |
Travel motor control block diagram for machines in the following serial number ranges: BDR2001-UP, BDM2001-UP, BDX2001-UP, BCZ2001-UP, BDK2001-UP, BDY2001-UP, BEB2001-UP, H2A1-UP, H2B1-UP, H2C1-UP, H2D1-UP, H2E1-UP, H2F1-UP and H2G1-UP. | |
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| Illustration 6 | g01152763 |
Travel motor control connections for machines in the following serial number ranges: BDR2001-UP, BDM2001-UP, BDX2001-UP, BCZ2001-UP, BDK2001-UP, BDY2001-UP, BEB2001-UP, H2A1-UP, H2B1-UP, H2C1-UP, H2D1-UP, H2E1-UP, H2F1-UP and H2G1-UP. | |
The ECM controls the speed and torque of the travel motor by sending a variable output current to the travel motor swash plate angle limit solenoid. This solenoid will cause the travel motor swash plate to increase or decrease the hydraulic flow through the travel motor. The ECM will monitor the inputs from the travel pedal position sensor and the transmission output speed sensor in order to determine the current output. The ECM also looks at the defined maximum machine speed parameter that is programmable in the Monitor or by using Cat ET. The four possible programmable speed settings are:
- 20 km/h (12.4 mph)
- 25 km/h (15.5 mph)
- 30 km/h (18.6 mph)
- 34 km/h (21.1 mph)
The default speed setting is 20 km/h (12.4 mph).
The ECM will use an internal formula calculation in order to determine machine ground speed. This formula takes into consideration the radius of the wheels, the axle ratio and the transmission speed. If the ECM detects that machine ground speed is 7 km/h (4.3 mph) over the defined maximum machine speed parameter, then an 83-2 "TRANSMISSION OVERSPEED" event code will be activated.
In order to enable smooth acceleration at the start of travel, the ECM will energize the travel motor bypass solenoid according to set parameters in the software. When this solenoid is energized, a small amount of hydraulic oil is allowed to bypass the travel motor for a short period of time during acceleration.
If an active diagnostic code occurs for the transmission speed sensor, the ECM will activate the limp home mode. Engine rpm will be limited.
The ECM will also control the braking function of the travel motor by limiting the travel motor swash plate angle with the travel motor swash plate angle limit solenoid. A programmable braking parameter can be changed in the Monitor or by using Cat ET. The three levels of braking and their assigned numbers are:
- Hard (High) braking
- Medium braking
- Soft (Low) braking
A travel motor calibration procedure should be performed when the machine is initially put in service or when travel motor performance is not satisfactory. Refer to Testing and Adjusting, "Travel Motor Speed - Calibrate" for this calibration procedure.