14L Motor Grader All Wheel Drive Electronic Control System Caterpillar

Test for the AWD Pump and AWD Motor

1. Start the machine.

2. Set the engine speed to 1600 ± 50 RPM.

3. Open Caterpillar Electronic Technician (Cat ET).

4. Select AWD ECM. Navigate to the "Override" screen.

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Illustration 1	g01360642

5. Verify that the AWD left front speed ratio reads zero for the left side prior to applying any overrides.

   ReferenceIf the left front speed ratio (A) is not zero, refer to the AWD ECM Testing and Adjusting, "Piston Pump Neutral - Test and Adjust" Story in this manual for more information.

6. Override the left front drive pump forward control solenoid current percentage override command to 100 percent.

7. Record the left front speed ratio. This ratio should be between 0.700 and 0.745.

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Illustration 2	g01362988

8. Override the left front drive motor solenoid current percentage override command to 100 percent.

9. Record the left front speed ratio. This ratio should be between 2.41 and 2.64.

10. Disable all overrides.

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Illustration 3	g01362989

11. Override the left front drive pump reverse control solenoid current percentage override command to 100 percent.

12. Record the left front speed ratio. This ratio should be between − 0.700 and − 0.745.

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Illustration 4	g01362990

13. Override the left front drive motor solenoid current percentage override command to 100 percent.

14. Record the left front speed ratio. This ratio should be between − 2.41 and − 2.64.

15. Disable all overrides.

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Illustration 5	g01362991

16. Verify that the AWD right front speed ratio reads zero for the left side prior to applying any overrides.

    ReferenceIf the right front speed ratio (A) is not zero, refer to the AWD ECM Testing and Adjusting, "Piston Pump Neutral - Test and Adjust" Story in this manual for more information.

17. Override the right front drive pump forward control solenoid current percentage override command to 100 percent.

18. Record the right front speed ratio. This ratio should be between 0.700 and 0.745.

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Illustration 6	g01362992

19. Override the right front drive motor solenoid current percentage override command to 100 percent.

20. Record the right front speed ratio. This ratio should be between 2.41 and 2.64.

21. Disable all overrides.

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Illustration 7	g01362994

22. Override the right front drive motor solenoid current percentage override command to 100 percent.

23. Record the right front speed ratio. This ratio should be between − 0.700 and − 0.745.

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Illustration 8	g01362995

24. Override the right front drive motor solenoid current percentage override command to 100 percent.

25. Record the right front speed ratio. This ratio should be between − 2.41 and − 2.64.

26. Disable all overrides.

27. Use the values that were recorded in Steps 6, 8, 11, and 13 with the following table in order to identify the appropriate corrective action that is required for the left side of the machine.

28. Use the values that were recorded in Steps 17, 19, 22, and 24 with the following table in order to identify the appropriate corrective action that is required for the right side of the machine.
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    Table 1

    	Forward Pump Ratio	Forward Motor Ratio	Reverse Pump Ratio	Reverse Motor Ratio	Possible Problem	Possible Corrective Action
    Nominal	0.722	2.491	− 0.722	− 2.491
    Min	0.700	2.410	− 0.700	− 2.410
    Max	0.745	2.640	− 0.745	− 2.640
    	OK	OK	OK	OK	The pump and the motor displacements are set correctly.	No adjustments are required.
    	OK	OK	Low, Ok	Low, Ok	The displacement of the reverse pump is set too low.	Increase the displacement of the reverse pump.
    	OK	OK	High, Ok	High, Ok	The displacement of the reverse pump is set too high.	Decrease the displacement of the reverse pump.
    	OK	Low	OK	Low	The minimum displacement of the motor is set too high.	Increase the minimum displacement of the motor.
    	OK	Low	Low	Low	The minimum displacement of the motor is set too high and the displacement of the reverse pump is set too low.	First, decrease the minimum displacement for the motor in order to correct the forward motor ratio. Next, increase the displacement of the reverse pump in order to correct the reverse pump ratio and the reverse motor ratio.
    	OK	Low	High	Low, High, Ok	The minimum displacement of the motor is set too high and the displacement of the reverse pump is set too high.	First, decrease the minimum displacement for the motor in order to correct the forward motor ratio. Next, decrease the displacement of the reverse pump in order to correct the reverse pump ratio and the reverse motor ratio.
    	OK	High	OK	High	The minimum displacement of the motor is set too low.	Increase the minimum displacement of the motor.
    	OK	High	Low	Low, High, Ok	The minimum displacement of the motor is set too low and the displacement of the reverse pump is set too low.	First, increase the minimum displacement for the motor in order to correct the forward motor ratio. Next, increase the displacement of the reverse pump in order to correct the reverse pump ratio and the reverse motor ratio.
    	OK	High	High	High	The minimum displacement of the motor is set too low and the displacement of the reverse pump is set too high.	First, decrease the displacement for the reverse pump in order to correct the reverse pump ratio. Next, increase the minimum displacement for the motor in order to correct the forward motor ratio and the reverse motor ratio.
    	Low, Ok	Low, Ok	OK	OK	The displacement of the forward pump is set too low.	Increase the displacement for the forward pump.
    	Low	OK	Low	OK	The maximum displacement of the motor is set too high.	Decrease the maximum displacement for the motor.
    	Low	OK	Low	Low	The maximum displacement of the motor is set too high and the displacement of the reverse pump is set too low.	First, decrease the maximum displacement for the motor in order to correct the forward pump ratio. Next, increase the displacement for the reverse pump in order to correct the reverse pump ratio and the reverse motor ratio.
    	Low	OK	Low, High	High	The maximum displacement of the motor is set too high and the displacement of the reverse pump is set too high.	First, decrease the maximum displacement for the motor in order to correct the forward pump ratio. Next, decrease the displacement for the reverse pump in order to correct the reverse pump ratio and the reverse motor ratio.
    	Low	Low	OK	Low	The minimum displacement of the motor is set too high and the displacement of the forward pump is set too low.	First, decrease the minimum displacement for the motor in order to correct the reverse motor ratio. Next, increase the displacement for the forward pump in order to correct the forward pump ratio and the forward motor ratio.
    	Low	Low	Low	OK	The maximum displacement of the motor is set too high and the displacement of the forward pump is set too low.	First, decrease the maximum displacement for the motor in order to correct the reverse pump ratio. Next, increase the displacement for the forward pump in order to correct the forward pump ratio and the forward motor ratio.
    	Low	Low, High, Ok	OK	High	The minimum displacement of the motor is set too low and the displacement of the forward pump is set too low.	First, increase the minimum displacement for the motor in order to correct the reverse motor ratio. Next, increase the displacement for the forward pump in order to correct the forward pump ratio and the forward motor ratio.
    	Ok, High	Ok, High	OK	OK	The displacement of the forward pump is set too high.	Decrease the displacement for the forward pump.
    	Low, High	Low	High	OK	The maximum displacement of the motor is set too low and the displacement of the forward pump is set too low.	First, increase the maximum displacement for the motor in order to correct the reverse motor ratio. Next, increase the displacement for the forward pump in order to correct the forward pump ratio and the forward motor ratio.
    	Low, High	High	Low	OK	The maximum displacement of the motor is set too high and the displacement of the forward pump is set too high.	First, decrease the maximum displacement for the motor in order to correct the reverse pump ratio. Next, decrease the displacement for the forward pump in order to correct the forward pump ratio and the forward motor ratio.
    	High	OK	Low, High	Low	The maximum displacement of the motor is set too low and the displacement of the reverse pump is set too low.	First, increase the maximum displacement for the motor in order to correct the forward pump ratio. Next, increase the displacement for the reverse pump in order to correct the forward motor ratio and the reverse motor ratio.
    	High	OK	High	OK	The maximum displacement of the motor is set too low.	Increase the maximum displacement for the motor.
    	High	OK	High	High	The maximum displacement of the motor is set too low and the displacement of the reverse pump is set too high.	First, increase the maximum displacement for the motor in order to correct the forward pump ratio. Next, decrease the displacement for the reverse pump in order to correct the forward motor ratio and the reverse motor ratio.
    	High	High	OK	High	The minimum displacement of the motor is set too low and the displacement of the forward pump is set too high.	First, increase the minimum displacement for the motor in order to correct the reverse motor ratio. Next, decrease the displacement for the forward pump in order to correct the forward motor ratio and the forward pump ratio.
    	High	High	High	OK	The maximum displacement of the motor is set too low and the displacement of the forward pump is set too high.	First, increase the maximum displacement for the motor in order to correct the reverse pump ratio. Next, decrease the displacement for the forward pump in order to correct the forward motor ratio and the forward pump ratio.
    	High	Low, High, Ok	OK	Low	The minimum displacement of the motor is set too high and the displacement of the forward pump is set too high.	First, decrease the minimum displacement for the motor in order to correct the reverse motor ratio. Next, decrease the displacement for the forward pump in order to correct the forward motor ratio and the forward pump ratio.
    	All of the measured ratios are out of tolerance. If the pump was adjusted more than 1/4 turns counterclockwise. If the pump was adjusted more than 2 turns clockwise.				Multiple adjustments have been incorrectly made.	Set the pump displacements to the default setting. Adjust the setting of the motor displacements in order to achieve the correct ratios.
    	The diagnostic sequence is not listed in this table.				An electrical problem or a problem with a solenoid	Refer to the AWD ECM Testing and Adjusting, "Solenoid Valve (Pump Displacement) - Test" for more information. Refer to the AWD ECM Testing and Adjusting, "Solenoid Valve (Motor Displacement) - Test" for more information.

Adjust for the AWD Pump and the AWD Motor

Illustration 9	g01360806
The left side motor is shown. (1) Adjustment screw for the maximum motor displacement (2) Adjustment screw for the minimum motor displacement

1. In order to decrease the maximum displacement of the motor for the left side of the machine, turn screw (1) clockwise. This will increase the forward pump ratio and the reverse pump ratio by approximately 0.04 per revolution.

2. In order to increase maximum displacement for the motor for the left side of the machine, turn screw (1) counterclockwise. This will decrease the forward pump ratio and the reverse pump ratio by approximately 0.04 per revolution.

3. In order to decrease the minimum displacement for the motor for the left side of the machine, turn screw (2) counterclockwise. This will increase the forward motor ratio and the reverse motor ratio by approximately 0.15 per revolution.

4. In order to increase the minimum displacement for the motor for the left side of the machine, turn screw (2) clockwise. This will decrease the forward motor ratio and the reverse motor ratio by approximately 0.15 per revolution.

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Illustration 10	g01362982
The right side of machine is shown. (1) Adjustment screw for the minimum motor displacement (2) Adjustment screw for the maximum motor displacement

1. In order to decrease the maximum displacement of the motor for the right side of the machine, turn screw (2) clockwise. This will increase the forward pump ratio and the reverse pump ratio by approximately 0.04 per revolution.

2. In order to increase maximum displacement for the motor for the right side of the machine, turn screw (2) counterclockwise. This will decrease the forward pump ratio and the reverse pump ratio by approximately 0.04 per revolution.

3. In order to decrease the minimum displacement for the motor for the right side of the machine, turn screw (1) counterclockwise. This will increase the forward motor ratio and the reverse motor ratio by approximately 0.15 per revolution.

4. In order to increase the minimum displacement for the motor for the right side of the machine, turn screw (1) clockwise. This will decrease the forward motor ratio and the reverse motor ratio by approximately 0.15 per revolution.