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| Here this info is right from the JD tech manual
HCU 052 — Hitch Draft Sensor Circuit Fault
The following test is used to troubleshoot this Service Code. Refer to manual links for supporting information.
HCU Test Procedure No. 5
HCU Test Procedure No. 05
Draft Sensor Test
-: Draft Sensor
HCU Address
Specification
Circuit Description
Related Diagnostic Code Number (HCU)
05
1.9 to 2.1 Volts (No Load Output)
Draft Sensor
052
Draft Sensor Test
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1 Hitch Draft Sensor
Action:
NOTE:
Remove implement from the hitch. (Implement quick coupler can remain in place.)
With the engine OFF, access HCU Address 05.
Voltage reading on the corner post display should be between:
-: Corner Post Display
05
1.90
....and....
-: Corner Post Display
05
2.10
NOTE:
The calibration logic of the HCU also checks this voltage reading but allows more tolerance than shown above. This is necessary to allow slight shifts in the draft sensor signal without requiring mechanical adjustments.
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Result:
OK: GO TO 2 .
NOT OK: If voltage is less than 0.35 volts.
GO TO 3 .
NOT OK: If voltage is more than 4.65 volts.
GO TO 4 .
NOT OK: If voltage is between 0.35 and 4.65 volts.
GO TO 5 .
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2 Draft Voltage
Action:
Attach a heavy 3-point implement.
Observe corner post display while implement is first lifted off the ground.
If the draft sensor is good, the voltage reading will DECREASE by 0.30 volts, or more, when the implement is first lifted off the ground.
Lower the implement to the ground.
Voltage reading on the corner post display should be within ±0.10 volt of the original voltage reading at 1 .
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Result:
OK: Sensor is good. If problem still exists, recalibrate the hitch. See Hitch Calibration in Section 270, Group 20. Also, review the Operators Manual for operation of the draft sensor feature.
NOT OK: If voltage does not change, check sensor for binding.
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3 Voltage Reading Less Than 0.35 Volts
Action:
Check the continuity of the harness from the draft sensor to the HCU.
NOTE:
Refer to hitch system wiring diagram. See HCU and SCU Wiring Harness Diagram , in this Group.
All circuits should have continuity.
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Result:
OK: Adjust the sensor.
GO TO 5 .
NOT OK: Repair the harness as necessary and calibrate the hitch.
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4 Voltage Reading More Than 4.65 Volts
Action:
Unplug the draft sensor connector.
Voltage reading on the corner post display should be:
-: Corner Post Display
05
000
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Result:
OK: Adjust the sensor.
GO TO 5 .
NOT OK: Circuit 884 is shorted. Repair the harness and calibrate the hitch. See Hitch Calibration in Section 270, Group 20.
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5 Voltage Reading Out of Range
Action:
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CAUTION:
To prevent the possibility of unexpected hitch movement, shut the engine OFF before adjusting the draft sensor.
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Connect test leads.
NOTE:
When DFRW65 Tap Out Harness is not available, select HCU Address 05 to read sensor voltage on corner post display and GO TO 6 .
With key switch OFF, disconnect 3-way connector at load/draft sensor (forward of rear axle by left side frame) and install DFRW65 Tap Out Harness in series at the load/draft sensor connector.
To make Tap Out Harness, see Section 299, DFRW635, DFRW64, DFRW65, DFRW66, DFRW81—Tap-Out Harnesses .
Install two 150 mm (6.0 in.) leads to 'A' and 'B' terminals of the DFRW65 Tap-out harness and attach digital multimeter to these leads.
The black lead of the multimeter should be connected to the 'A' lead.
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Result:
OK: GO TO 6 .
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6 Check Sensor Output Voltage
Action:
Key switch ON, engine OFF.
Voltage should be between 1.9 and 2.1 volts with no draft load.
NOTE:
The output voltage will increase with an increasing draft load and decrease with a decreasing draft load.
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Result:
OK: Voltage within specification. Calibrate hitch, then check operation. See Hitch Calibration in Section 270, Group 20.
NOT OK: GO TO 7 .
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7 Adjust Draft Sensor Output Voltage
Action:
RW22798-UN: Draft Load Sensor
LEGEND:
A - Load/Draft Sensor
B - 3-Way Connector
C - Turnbuckle
D - Decrease Voltage
E - Increase Voltage
Turn key switch ON.
Install DFRW65 Tap Out Harness in series to the load/draft sensor connector (B).
Loosen jam nuts on turnbuckle (C) under right, rear of tractor, forward of differential housing.
Rotate turnbuckle (C) with screwdriver to get 1.9 to 2.1 volts.
Adjust sensor lever toward left side (D) to decrease voltage or toward right side (E) to increase voltage.
Tighten jam nuts and recheck voltage. Readjust turnbuckle, if necessary, until voltage is within specification when jam nuts are tight.
NOTE:
Voltage setting may shift when jam nuts are tightened.
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Result:
OK: Sensor output voltage adjusted to specification. Calibrate hitch, then check operation.
NOT OK: Sensor output voltage cannot be adjusted.
GO TO 8 .
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8 Resistance Check of Hitch Harness to Load/Draft Sensor
Action:
Turn key switch OFF.
Disconnect DFRW65 Tap Out Harness from load/draft sensor harness.
Disconnect hitch harness from HCU 30-way connector (A4X1).
With voltmeter, check the following circuits from the HCU connector to the load/draft sensor terminals for less than 1.0 ohm resistance according to the following chart. (See HCU and SCU Wiring Harness Diagram , in this Group.)
-: Resistance Check of Hitch Harness
HCU Connector
PIN Wire
Load/Draft
Terminal Wire
Circuit
Number
2A3....
A....
871
1F1....
B....
884
2A2....
C....
873
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Result:
OK: Resistance readings within specification. Check HCU and load/draft sensor terminals, if bad, repair as necessary and calibrate hitch. If terminals are good, replace load/draft sensor and calibrate hitch. Then check hitch operation. See HCU and SCU Wiring Harness Diagram , in this Group.
NOT OK: Repair harness, then....
GO TO 6 .
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9 Hitch Sensitivity Check
Action:
Start engine and set speed at slow idle.
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CAUTION:
Stand clear of hitch linkage during test.
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Turn load/depth control knob to full CW.
Move hitch control to raise hitch approximately 1/4 from full down position.
Using an adjustable wrench, place jaws on link that operates load/draft sensor near pivot point and twist wrench using a long screwdriver.
Observe hitch movement and voltage readings according to the following chart.
-: Hitch Movement and Voltage Readings
Wrench
Rotation
Sensor
Motion
Voltage
Reading
Hitch
Movement
Load
Simulation
CW
Inward
Decrease
Down
Decreasing
CCW
Outward
Increase
Up
Increasing
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Result:
OK: Load/Draft sensor sensitivity is normal.
GO TO 10 .
NOT OK: Hitch response is not normal, replace load/draft sensor and calibrate hitch. See Hitch Calibration in Section 270, Group 20.
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10 Visually Inspect Load/Draft Sensor Harness
Action:
Turn key switch and engine OFF.
Disconnect DFRW65 Tap Out Harness from load/draft sensor harness.
Inspect load/draft sensor harness chaffing and harness connectors for proper engagement.
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Result:
OK: Harness and connectors ok, connect load/draft sensor harness.
NOT OK: Repair harness and connectors as necessary and calibrate hitch. See Hitch Calibration in Section 270, Group 20.
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TD21397,00001B9-19-20030207
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JD 9300 has code. HCU 52
