Usage:
AP-1050B (6ZN),
AP-1055B (8BM),
AP-1000B (7HN),
AP-650B (9DN),
BG-2455C (6TN),
BG-245C (4XN),
BG-260C (8GN),
BG-225C (5GN) Asphalt Pavers
- Submode c11 on Wheel Pavers
- Submode c12 on Track Pavers
Problem: During the initial propel current auto calibration, the situation has occurred in which the propel fault lamp turned OFF when the propel lever was stroked forward but never flashed to indicate completion of the auto calibration.
Solution: When performing the auto calibration for initial propel current, the propel fault lamp will turn ON. At this time, the propel speed lever should be moved to the maximum forward position. This will cause the lamp to turn OFF if all the initial calibration criteria have been met. With the lamp OFF, the machine will begin to slowly propel forward until the speeds of both motors have smoothed out. When the current has leveled out to a constant value, the propel fault lamp will begin to flash indicating that the calibration is complete.
Using a multimeter, the speed sensor frequency can be obtained in order to determine if the control module is receiving an adequate signal for calibration. If the frequency signals are not within the range shown in the table above, the MPC-10 will not calibrate. This will prevent the propel fault lamp from flashing to indicate completion of the calibration.
In order for the calibration to occur, the propel motors must achieve speeds of 90 ± 20 RPM. This converts to an equivalent speed sensor frequency for each machine as shown in the following table:
In the event that the propel fault lamp does not flash and the speed sensor frequency is not correct for calibration, check the following solutions:
1. Is there current to the propel pump EDCs to stroke the pumps? During calibration, the MPC-10 could send a maximum current of 32 mA to the pump EDCs. To check this, install a multimeter in series on the forward propel pump EDC pins (numbers 10 and 31) at the 40 pin connector which plugs into the MPC-10. This same situation may occur in the reverse calibration. In this case, the multimeter should be connected in series with the reverse propel pump EDC pins (numbers 11 and 34).
2. Are the pumps nulled correctly? If the propel pumps are not nulled correctly, the EDCs may require more that 32 mA to stroke the pumps enough to propel the machine. Since this exceeds the maximum current that can be sent to the EDCs during calibration, the machine will not calibrate. (Reference December 1, 1997 Service Magazine article for this pump nulling procedure, and attempt to recalibrate the initial propel currents after the propel pumps are nulled.)
3. Are the pump EDCs sticking? If there is current to the pump EDC and the servo piston pressure does not change on ports M4 and/or M5, the EDC might be sticking and should be replaced.
4. Are the speed sensors sending a good signal to the propel control module? The consistency of the frequency signal can be checked using a multimeter set to read Hertz. If the signal is bad, there may be three possible explanations:
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- * The speed sensor adjustment may be incorrect. If the sensor is not turned in far enough, it may not be able to clearly detect the passing gear teeth. This can prevent the sensor from generating a signal or cause it to send an inconsistent signal to the control module.
- * The speed sensor itself may be defective.
- * There may be a short somewhere in the system which is preventing the transmission of the frequency signal from the speed sensor to the control module.
- * The speed sensor adjustment may be incorrect. If the sensor is not turned in far enough, it may not be able to clearly detect the passing gear teeth. This can prevent the sensor from generating a signal or cause it to send an inconsistent signal to the control module.