KIT-REPAIR 1544386 - Caterpillar

Table 1
Duty Cycles for ACJ Thumbwheels When Used For Grade Control
0 - 5% Shorted Low
5 - 20% No Command
20 - 45% Decrement
45 - 55% Center Position - No Command
55 - 95% Increment
95 - 100% Shorted High/Open Circuit Test Step 1. CHECK THE SENSOR POWER SUPPLY CIRCUIT
Turn the disconnect switch and the key start switch to the ON position.
At the J1 harness connector for the right ACJ, insert 7X-1710 Multimeter Probes along the +8V power supply contact J1-1 (wire 709-OR(Orange)) and along ground contact J1-2 (wire A295-BK(Black)). Do not disconnect the machine harness from the J1 connector.
Measure the DC voltage of the sensor power supply.Expected Result:Each voltage measurement is approximately 8.0 0.4 VDC.Results:
OK - The voltage measurement is approximately 8.0 0.4 VDC. The power supply for the sensor is correct. Proceed to Test Step 2.
NOT OK - The voltage measurements are less than 8.0 0.4 VDC. The power supply for the sensor is not correct. Repair: If the voltage measurement is not correct, the problem is most likely in the power circuit wire. This condition will cause multiple diagnostic codes to activate.Refer to the complete Electrical System Schematic of the machine. Examine all the connectors that are in the circuits. Ensure that the connections are clean, that all connections are secure, and that all connections are in good condition.For troubleshooting the ECM power supply that is providing power to the sensor, refer to the CID 0041 diagnostic code procedures in the troubleshooting section of the manual for the Implement ECM.Repair the defective power supply circuit before proceeding with this procedure.STOPTest Step 2. CHECK FOR AN OPEN IN THE SENSOR CIRCUIT
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector from the right ACJ. At the harness connectors for the ACJ, place a jumper wire between the ground contact J1-2 (wire A295-BK(Black)) and the signal contact J1-3 (wire T979-YL(Yellow)).
Disconnect machine harness connectors J1 and J2 from the Implement ECM.
At the harness connector for the Implement ECM, measure the resistance from return contact J1-45 (wire A295-BK(Black)) to signal contact J2-50 (wire T979-YL(Yellow)).
Observe the resistance measurement while you wiggle the ECM connector and the sensor connector. Gently pull on the wires and move the wires around for both connectors.Expected Result:The resistance measurement is less than 5 ohms always during the manipulation of the wiring harness and connectors.Results:
OK - The resistance measurement is less than 5 ohms. The signal circuit of the sensor and the ground circuits of the sensor are not open in the machine harness. Proceed to Test Step 3.
NOT OK - The resistance measurement for the signal circuit is greater than 5 ohms. There is an open or a bad connection in the circuit.Repair: Check the signal circuit for opens or for a bad connection.A resistance measurement that is greater than 5 ohms but less than 5000 ohms would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5000 ohms