SCREW-SELF-TAPPING 2802741 - Caterpillar

Illustration 1 g03326624
Connections of the blade control handle position sensors
The CID 1079 diagnostic code is associated with the blade tilt position sensor. The FMI 03 diagnostic code means the input signal from the sensor and the signal voltage is above the acceptable range.Two separate position sensors are required for correct operation of the blade control. Each sensor provides an input signal to the ECM that indicates the position of the blade control handle. The signal receives power from the battery. The position sensor sends a PWM input signal to the Implement ECM. The duty cycle of the signal varies from approximately 90 percent at the full right position to approximately 10 percent at the full left position. When the blade control handle is at the center position, the duty cycle will be approximately 50 percent.Possible causes of the diagnostic code are listed below:
The power supply circuit is open.
The fuse has blown.
The return circuit is open.
The signal circuit is open.
The signal circuit is shorted to another voltage source
The position sensor has failed.
The ECM has failed. This condition is unlikely.System Response:
A level 2 warning will be generated.
The machine will lose all ability to tilt the blade.
The "limp home" function is available.
Solenoid overrides are available.Note: Ensure that the CID 1079 FMI 03 diagnostic code is active. This procedure can cause new diagnostic codes to be recorded. Ignore these created diagnostic codes. When the procedure is completed, clear the created diagnostic codes.Test Step 1. CHECK THE POWER SUPPLY CIRCUIT TO THE SENSOR
Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.
At the machine harness connector for the sensor, insert a multimeter probe along contact "1" wire (176-OR(Orange)) and along contact "2" wire (210-BK(Black)). Do not disconnect the machine harness connector from the sensor.
Measure the voltage. Expected Result:The voltage measurement is between 23.5 VDC and 24.5 VDC.Results:
OK - The voltage measurement is between 23.5 VDC and 24.5 VDC. The power circuits for the sensor are correct. Proceed to Test Step 2.
NOT OK - The voltage measurement is less than 23.5 VDC. The power supply for the sensor is not correct.Repair: There is an open circuit or a bad connection in the machine harness. Verify that the fuse is in good condition and is not blown. Wire (176-OR(Orange)) may have an open circuit. Refer to the complete Electrical System Schematic for your machine. Examine all of the connectors that are in the circuit. Ensure that the connections are clean and secure. Repair the machine harness or replace the machine harness.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 connector from the sensor. At the harness connector for the sensor, place a jumper wire between contact "2" (wire 210-BK(Black)) and the contact "5" (wire H710-PK(Pink)).
Disconnect the J1 and J2 machine harness connectors from the ECM.
At the machine harness connectors for the ECM, measure the resistance between contact J1-13 wire (210-BK(Black)) and contact J2-24