SUPPORT 3900856 - Caterpillar

Illustration 1 g02627957
Connections of the winch control handle brake/free spool position sensor.
This diagnostic code is associated with the winch control handle brake/free spool position sensor. This sensor is also known as the "y-axis". The FMI 08 diagnostic code means that the input signal from the sensor is not within the expected range.The sensor provides an input signal to the ECM that indicates the position of the winch control handle brake/free spool function. 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 forward position to approximately 10 percent at the full rearward position. When the blade control handle is at the center position, the duty cycle will be approximately 50 percent. The possible causes of this diagnostic code are listed:
The sensor has failed.
Intermittent connections or poor connections exist in the sensor circuit.
The ECM has failed. An ECM failure is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 1881 - FMI 03 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. Check the duty cycle and the frequency of the signal at the sensorTurn the key start switch and the disconnect switch to the OFF position.
At the machine harness connector for the handle base, use a wire removal tool in order to remove wire (E850-BR(Brown)) and the socket from the harness connector. The machine harness connector remains connected to the sensor.
At the empty space in the machine harness connector for the handle base, use the positive multimeter probe to connect to pin 5 of the sensor. Insert the other probe along contact "2" wire (210-BK(Black)). Ensure that a good connection is made between the probes and the contacts.
Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.
Measure the frequency of the signal from the sensor while the direction/speed control lever is stationary.
Move the control lever through the full range that is described at the beginning of this procedure. Expected Result: The frequency of the signal is 500 80 Hz. The duty cycle of the signal is correct according to the description at the beginning of this procedure.Results:
YES - The frequency of the signal is 500 80 Hz. The duty cycle of the signal is correct according to the description at the beginning of this procedure. Reconnect the signal wire and the socket in the machine harness connector for the handle base. Verify that all of the wires are secure in the connector before proceeding to the next step. Proceed to Test Step 2.
NO - The signal frequency and the duty cycle of the signal is not correct according to the description at the beginning of this procedure. The sensor has failed.Repair: