CARBURETOR GP 4P2010 - Caterpillar

Illustration 1 g02440038
Connections of Auxiliary Third Function (Thumbroller) Position Sensor
This diagnostic code is associated with the Auxiliary Third Function (Thumbroller) Position Sensor. The position sensor is located in the right joystick. The Implement ECM 10 VDC sensor power supply and ground are used to power the position sensors.The FMI 08 diagnostic code is activated when a frequency or signal pulse width is detected that is not within the expected range.The position sensor is a PWM sensor that operates at a frequency of approximately 500 100 Hz. The position sensor sends a PWM input signal to the Implement ECM. The variations in the duty cycle of the signal follow:
Table 1
Thumbroller Position Acceptable Sensor PWM Duty Cycle (Percent)
Full Forward 85 to 93
Centered 45 to 55
Full Rearward 7 to 14 The possible causes of this diagnostic code are listed below:
The sensor has failed or a mechanical connection has failed.
Intermittent connections or poor connections
The ECM has failed. This condition is unlikely.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be 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. Ignore these created diagnostic codes and clear the diagnostic codes when the problem has been corrected.Test Step 1. CHECK THE DUTY CYCLE AND THE SIGNAL FREQUENCY AT THE SENSOR
Turn the key start switch and the disconnect switch to the OFF position.
At the machine harness connector X-C1 for the right joystick, use a 151-6320 Removal Tool to remove the signal wire H722-GN(Green) and the socket at contact 3 from the harness connector. The machine harness connector X-C1 remains connected to the right joystick.
Turn the disconnect switch and the key start switch to the ON position.
At the connector X-C1 for the right joystick, insert a 7X-1710 Multimeter Probe along the return contact of the sensor 2 (wire J765-BU(Blue)).
Use the other multimeter probe to make contact through the harness connector with pin 2 for the position sensor on the joystick connector.
With the thumbroller in the stationary condition, measure the frequency of the signal from the sensor.
Measure the duty cycle of the sensor signal between the connector contacts 3 and 2 of the right joystick. Slowly move the thumbroller to the full forward position and observe the duty cycle of the sensor signal. Slowly move the thumbroller to the full rearward position and observe the duty cycle of the sensor signal. Expected Result:The frequency of the position sensor is 500 100 Hz. The duty cycle of the position sensor is correct according to the description at the beginning of this procedure. Results:
OK - The signal frequency and the duty cycle of the sensor is correct. The sensor is not the cause of the problem. Reconnect the signal wire and