BUCKET GP-ADJ& 5106749 - Caterpillar

Illustration 1 g02771378
Connections of the Loader Joystick Thumbwheel position sensor
This diagnostic code is associated with the Loader Joystick Thumbwheel position sensor. The position sensor provides a PWM input signal to the Machine ECM. The position sensor is embedded in the loader joystick handle. The FMI 04 diagnostic code is activated when the ECM reads the input signal from the sensor and the voltage is below normal.The sensor is a PWM sensor that operates at a frequency of approximately 500 100 Hz. The duty cycle of the PWM signal that is supplied to the ECM is measured in small increments. The changes in the duty cycle of the sensor cannot be measured with a digital multimeter.The following conditions could cause this diagnostic code to be activated:
The signal circuit is shorted to a ground source.
The sensor has failed.
The ECM has failed. This condition is unlikely.Note: Before performing this procedure, check for an active CID 0041 diagnostic code for the 8V sensor power supply of the Machine ECM. Correct any problem with the 8V power supply before performing this procedure.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections are often the cause of a problem in an electrical circuit. Inspect the connections for the following:
Connections are clean.
Connections are secure.
Connections are in good condition.If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.Note: The following test procedure may create other diagnostic codes. Clear the diagnostic codes when the original diagnostic code has been corrected.Test Step 1. CHECK THE SENSOR
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the machine harness connector from the position sensor. Observe the status of the active CID 2529 FMI 04 diagnostic code.
Observe the status of the active diagnostic code for the sensor. Expected Result:The status of the CID 2529 FMI 04 diagnostic code did not change when the position sensor was disconnected. A CID 2529 FMI 03 diagnostic code has not been activated by the ECM. The CID 2529 FMI 04 diagnostic code remains active when the sensor disconnected.Results:
OK - The CID 2529 FMI 04 diagnostic code remains active when the sensor is disconnected. The sensor is not the cause of the problem. Proceed to Test Step 2.
NOT OK - The status of the CID 2529 FMI 04 diagnostic code is no longer active when the sensor was disconnected. The CID 2529 FMI 03 diagnostic code is activated by the ECM when the position sensor is disconnected. The machine harness and ECM are operating correctly.Repair: The operation of the position sensor is the cause of the problem. Replace the loader joystick . After replacement of the joystick, verify that the operation is correct before operating the machine.STOPTest Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector from the position sensor.
Disconnect the J1 and J2 machine